Not the GP, but here is my website with photos with different aspect ratios. I used display:inline-block to achieve this result, effectively treating photos as text that needs to reflow.
Proper masonry layouts which fill all available space in practice actually crop some images. Leaving space around photos is required when you don’t want cropping and want to preserve aspect ratio. That’s why I prefer my solution over what JS libraries for masonry layouts do.
https://yakubin.com/photography/albumless/
https://yakubin.com/photography/album/kenya-2023/
Proper masonry layouts which fill all available space in practice actually crop some images. Leaving space around photos is required when you don’t want cropping and want to preserve aspect ratio. That’s why I prefer my solution over what JS libraries for masonry layouts do.