I'm not totally sure if this the right spot for this, so if it's not I'm sorry!

I'm wanting to spruce up my cat and dog galleries. Adding background images and stuff. But for some reason when I try to code the background, it just shows up as a small framed tile?

I don't know if Subeta uses different code? haha. But I just really would love to spruce up my galleries.

Thanks so much!