An idea for a quality of life improvement:
Currently the user is able to use arrow keys to navigate between the pictures currently shown in the grid.
The user can also switch to the previous/next page using n or p.

Intuitively, I think it would make sense to automatically switch to the next/previous page, when navigating past the borders of the current page, while remaining in the same row from the previous page.

Example:

When the user is at the rightmost image on the left page, the right-arrow key should switch to leftmost image on the next page, while remaining in the same row as the previous page (In this example, the middle row).
Obviously, the same logic should apply when switching to the previous page.

In my opinion, its good to have both options available:

• Switch pages with n or p (fast navigation through images, to quickly find one)
• Automatic page switching with arrow keys (slow navigation, when actually looking at the images)

I hope you don't mind all these suggestion issues ;)