The next button displays photos backward.
Yes, it goes to the first photo added to the album as seen at our demo if you start at the first one on the top left. You can see the photo numbers when you are clicking next / previous. So if you go here https://demo.socialengine.com/albums/view/8/landscapes and click the top left, that was the last one added to the album. Logically, when you reach the end of a list of things that start over like this, it would then go to the first one and resume. If you look at the numbers, you will see what I mean. This makes sense as it shows the photos most recent first because normally, people want to see the most recent content before seeing old content as many have already seen the old content. For a site with a million photos going from 2020 back to 1972, would you want your users having to view 1972 first and think, this site is very old and has no new content? Or would you prefer they see 2020 photos first to keep them engaged and seeing new stuff is being added?
We can consider an improvement to allow clients to choose between new content and old for the views.
We have improvements coming for photo sort order and for wall photo album order. I mean photos in the Wall Photos album.