How is that better? It's still a grid of images that seem to be constrained to a more or less rectangular grid. I'm thinking more of a dynamic grid where there is a mix of sizes of horizontal and vertical images.

The point being raised is that dynamic image grids don't actually make for a good UX. They might look more visually interesting at a superficial glance, but when you're actually using the interface to browse images, predictability wins out. Even having mixed-orientation images, where there is some degree of extra whitespace between images, does not change this. It is way easier to digest the content when your eyes can reliably scan one line at a time without having to bounce around everywhere to track the flow of the dynamic grid.

What is it with commenters in this thread and wanting to "reliably scan one line at a time?" When users use image galleries, they generally do jump around because they're looking at all the options on screen all at once. The eyes absorb everything and then they pinpoint what looks good. I've never seen or heard anyone go line by line in an image gallery or a newspaper layout and doing so I'd find to be highly abnormal to average users.

I suspect if data from eye-tracking tests were available, there would be an extremely clear revealed preference from users. I read image galleries the exact same way I skim text, in an ordered fashion that allows me to "read" every image without reading an image twice, stopping if my attention is caught by something in particular. Splotting garbage over the screen haphazardly makes it blend together annoyingly and results in my eyes traversing the same areas multiple times both to try to pick out details and to try to keep my place in what I have/haven't skimmed yet. It is a layout that itself demands my attention, rather than letting my attention be absorbed naturally by the actual images.

From actual eye tracking data via Hotjar and similar, people do skip around the page. Those that scan linearly are in the minority but probably are more highly represented on HN, just as a matter of course.