it's pretty simple, really. if you read the first post of the thread, it says that you claim the picture of the person above you. basically, you post saying you've claimed the person above you, then go to their profile and click on their photos, and leave a comment on one (or more, if you want to) of their pictures. hence, photo comments. the person who comments next will comment on one of your pictures, and so on. some people ask for a specific picture to be commented, so if you're the person who claims them, you have to comment on that picture. most people just say "any" or "newest please", so.
capiche?
just a btw, but you should really stop posting on the picture comment thread with questions/comments about the game, or any thread such as that, it's a bit disruptive. always be sure to read the first post of each game thread, because nine times out of ten it explains in plain language what is happening. if not, pm the maker of the thread and they should explain it to you. posting things unrelated to participation in the game could count as spam, and could result in a week's ban from the forms.
you and i are in the same boat. i'm worthless when it comes to reading most kanji. i have to have something on hand for that. and i can do fairly well with kana (but i usually refer to my dictionary just in case). no language classes here, though, so i'm kind of stuck learning it on my own.
and i'm not actually from japan. i'd love to be (trust me), but i'm stuck in the fail that is the states. T-T