New Amount in Categories

I have my photo blog set up to display one picture on the front page at a time:

https://urltea.com/14yc

However, when I click on a category, the results page only shows one result at a time, even though there are several:

https://thatnight.net/photo/?cat=5

This is also the same with search results.

Is there a way to make it so the category and search results pages shows the list of all results on one page, rather than only one at a time?

Thanks in advance!:)