There are two new ways for you to arrange photos in your posts. See the user guides for more details.
Up to now the photos you uploaded have displayed down the page with text inbetween if you added it. You can still create posts looking like that but now there are a couple of alternative ways to have your pictures displayed in a post.
Masonry image gallery
This will take your photos and arrange them in a block. Please note, this view is now the default when three or more pictures are uploaded but only if you don’t have any blank lines or text between the images. See the user guide for more details. It looks something like this:
Slideshow image gallery
Using this voew stacks your photos and adds left/right arrows to scroll through them as a slideshow. It works the same way on both desktop and mobile.