Personally, I don't like that much logic in the template. Even hate it. The code becomes unreadable. In such a case I would rather move all this intricate logic into the PHP part, doing some preprocessing that will result in the plain array, so the end code would be like this

<figure>
    <picture>
<?php foreach ($image['srcset'] as $row): ?>
        <source media="(orientation: <?=$row['orientation']?>)" type="image/<?=$row['format']?>" srcset="<?=$row['srcset'] ?>">
<?php endforeach ?>
        <img src="<?=$imagePath?>lg.jpg" width="1200" height="800" alt="<?=$image['caption']?>">
    </picture>
</figure>

The preprocessing PHP code should be exactly like your current code, just collecting the data into array instead of echoing it

$new = [];
foreach ($image['srcset']['ratio'] as $orientation => $ratio) {
    $basePath = "assets/img/{$image['name']}/{$image['name']}-{$ratio}";
    foreach($image['srcset']['format'] as $format) {
        $srcset = '';
        foreach($sizes as $size => $vw) {
            $srcset .= $srcset ? ",":"";
            $srcset .= "{$comma}{$basePath}-{$size}.{$format} {$vw}w"; 
        }
        $new[] = [
            'orientation' => $orientation,
            'format' => $format,
            'srcset' => $srcset,
        ];
    }
}

another possibility is to write sort of a helper function

<figure>
    <picture>
        <?php foreach ($image['srcset']['ratio'] as $orientation => $ratio): ?>
            <?php foreach($image['srcset']['format'] as $format): ?>
                <source media="(orientation: <?=$orientation?>)" type="image/<?=$format?>" srcset="<?=getsrcset($image, $ratio, $format, $key)">
            <?php endforeach ?>
         <? endforeach ?>
         <img src="<?=$imagePath?>lg.jpg" width="1200" height="800" alt="<?=$image['caption']?>">
     </picture>
</figure>

And two generic suggestions:

• short open tag is forbidden, always use <?php instead of <?
• do not neglect the code indentation. The proper formatting is very important, it helps to understand what does the code do

Personally, I don't like that much logic in the template. Even hate it. The code becomes unreadable. In such a case I would rather move all this intricate logic into the PHP part, doing some preprocessing that will result in the plain array, so the end code would be like this

<figure>
    <picture>
<?php foreach ($image['srcset'] as $row): ?>
        <source media="(orientation: <?=$row['orientation']?>)" type="image/<?=$row['format']?>" srcset="<?=$row['srcset'] ?>">
<?php endforeach ?>
        <img src="<?=$imagePath?>lg.jpg" width="1200" height="800" alt="<?=$image['caption']?>">
    </picture>
</figure>

The preprocessing PHP code should be exactly like your current code, just collecting the data into array instead of echoing it

$new = [];
foreach ($image['srcset']['ratio'] as $orientation => $ratio) {
    $basePath = "assets/img/{$image['name']}/{$image['name']}-{$ratio}";
    foreach($image['srcset']['format'] as $format) {
        $srcset = '';
        foreach($sizes as $size => $vw) {
            $srcset .= $srcset ? ",":"";
            $srcset .= "{$basePath}-{$size}.{$format} {$vw}w"; 
        }
        $new[] = [
            'orientation' => $orientation,
            'format' => $format,
            'srcset' => $srcset,
        ];
    }
}

another possibility is to write sort of a helper function

<figure>
    <picture>
        <?php foreach ($image['srcset']['ratio'] as $orientation => $ratio): ?>
            <?php foreach($image['srcset']['format'] as $format): ?>
                <source media="(orientation: <?=$orientation?>)" type="image/<?=$format?>" srcset="<?=getsrcset($image, $ratio, $format, $key)">
            <?php endforeach ?>
         <? endforeach ?>
         <img src="<?=$imagePath?>lg.jpg" width="1200" height="800" alt="<?=$image['caption']?>">
     </picture>
</figure>

And two generic suggestions:

• short open tag is forbidden, always use <?php instead of <?
• do not neglect the code indentation. The proper formatting is very important, it helps to understand what does the code do

Personally, I don't like that much logic in the template. Even hate it. The code becomes unreadable. In such a case I would rather move all this intricate logic into the PHP part, doing some preprocessing that will result in the plain array, so the end code would be like this

<figure>
    <picture>
<?php foreach ($image['srcset'] as $row): ?>
        <source media="(orientation: <?=$row['orientation']?>)" type="image/<?=$row['format']?>" srcset="<?=$row['sizes'] ?>">
<?php endforeach ?>
        <img src="<?=$imagePath?>lg.jpg" width="1200" height="800" alt="<?=$image['caption']?>">
    </picture>
</figure>

another possibility is to write sort of a helper function

<figure>
    <picture>
        <?php foreach ($image['srcset']['ratio'] as $orientation => $ratio): ?>
            <?php foreach($image['srcset']['format'] as $format): ?>
                <source media="(orientation: <?=$orientation?>)" type="image/<?=$format?>" srcset="<?=getsrcset($image, $ratio, $format, $key)">
            <?php endforeach ?>
         <? endforeach ?>
         <img src="<?=$imagePath?>lg.jpg" width="1200" height="800" alt="<?=$image['caption']?>">
     </picture>
</figure>

And two generic suggestions:

• short open tag is forbidden, always use <?php instead of <?
• do not neglect the code indentation. The proper formatting is very important, it helps to understand what does the code do

Personally, I don't like that much logic in the template. Even hate it. The code becomes unreadable. In such a case I would rather move all this intricate logic into the PHP part, doing some preprocessing that will result in the plain array, so the end code would be like this

<figure>
    <picture>
<?php foreach ($image['srcset'] as $row): ?>
        <source media="(orientation: <?=$row['orientation']?>)" type="image/<?=$row['format']?>" srcset="<?=$row['srcset'] ?>">
<?php endforeach ?>
        <img src="<?=$imagePath?>lg.jpg" width="1200" height="800" alt="<?=$image['caption']?>">
    </picture>
</figure>

The preprocessing PHP code should be exactly like your current code, just collecting the data into array instead of echoing it

$new = [];
foreach ($image['srcset']['ratio'] as $orientation => $ratio) {
    $basePath = "assets/img/{$image['name']}/{$image['name']}-{$ratio}";
    foreach($image['srcset']['format'] as $format) {
        $srcset = '';
        foreach($sizes as $size => $vw) {
            $srcset .= $srcset ? ",":"";
            $srcset .= "{$comma}{$basePath}-{$size}.{$format} {$vw}w"; 
        }
        $new[] = [
            'orientation' => $orientation,
            'format' => $format,
            'srcset' => $srcset,
        ];
    }
}

another possibility is to write sort of a helper function

<figure>
    <picture>
        <?php foreach ($image['srcset']['ratio'] as $orientation => $ratio): ?>
            <?php foreach($image['srcset']['format'] as $format): ?>
                <source media="(orientation: <?=$orientation?>)" type="image/<?=$format?>" srcset="<?=getsrcset($image, $ratio, $format, $key)">
            <?php endforeach ?>
         <? endforeach ?>
         <img src="<?=$imagePath?>lg.jpg" width="1200" height="800" alt="<?=$image['caption']?>">
     </picture>
</figure>

And two generic suggestions:

• short open tag is forbidden, always use <?php instead of <?
• do not neglect the code indentation. The proper formatting is very important, it helps to understand what does the code do