It's made up of many similar pictures put together, right?
It's composed of many pictures that are similar placed together.
ご質問ありがとうございます。
① "It's made up of many similar pictures put together, right?"＝「似たような沢山の写真を一緒にしてできているですね。」
② "It's composed of many pictures that are similar placed together."＝「似たような沢山の写真が同じ場所に置かれて作られているんですね。」
ご参考に。
It's made up of a lot of the same type of pictures, isn't it?
It has a lot of pictures that look alike, wouldn't you say?
この場合、次のように言えると思います。
ーIt's made up of a lot of the same type of pictures, isn't it?
「たくさんの同じ種類の写真からできてるんですね」
to be made up で「全体を構成する」
ーIt has a lot of pictures that look alike, wouldn't you say?
「たくさんの似たような写真からできているんですね」
It（モザイク写真）が has（持っている）と簡単に言うこともできますよ。
ご参考まで！
アメリカ合衆国 
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