It seems that instead of showing the images in their full aspect ratio, the profile gallery is a grid of square thumbnails. The notification yesterday from the development team said "infinite masonry profile media". Masonry being the technique used to interleave images of different sizes in a grid. Like Pinterest there.
Fixed square thumbs isn't quite the same as masonry, but it's using the same techniques here to get the infinite scroll to work with large quantities of images, so this is what we have.
The images are cropped centrally so you need to click on one to see it in its full glory (bonus: which registers as an interaction!) and from there, you can tap to scroll through... up until the next batch at least. When you reach the end of what's been lazy loaded next, you need to X out of the display mode, scroll down a bit and click another image to see them full size.