Hi Ismael.
Thanks for getting back to me. We are using Smush, which optimizes images in bulk. What we’re more interested in, besides srcset, is that we get the optimized avif image. This means that the theme should leverage WordPress’ wp_get_attachment_image function, which I see it does.

After examining avia-shortcodes/image/image.php I noticed that in some cases the image gets built in a custom way based off the following condition (is_numeric($src_original)).
Could you expand what are some practical cases when this happens?

Code screenshot: https://snipboard.io/r5YBgQ.jpg

Thanks,
Neven