Exactly your query is not clear, What you want to know. If you have images then you can put them under media and inside media, image section should be there.
Try to tell this in your own language maybe, than there is a chance someone will understand Because now it's hard to understand this.
Is it something to do with your blog (can't link it yet anyone who wants to know can find it through profile page) and putting pictures in categories could you add a bit extra for a description?
Gee guys, everyone feeling a bit mean-spirited or something? It says clearly that they have a pictures and images site and are asking which category they should submit it to. Sure there's not enough information for a complete answer but there's enough to get started. It depends a bit on what the pictures are of and what they can be used for. Celebrity picture sites can go under something like Art > Performers. Clip Art would probably go under Computers & Internet > Graphics Resources Coloring Pages might go under Home & Family > Children etc.
YMC is quite right, there are several different kinds of pictures, the niche of the picture/images submitted to your directory will determine which category it should be listed. Good luck.