"우리는 그 창문을 통해서 봅니다."

watch 이라는 건 대강 좀 더 오래 보는 듯이다 We watched the game. We watched the movie. We watched the children playing. 구경 이나 지카다는 듯 "Watch me." is used when we are teaching someone how to do something. "Look at me" is usually to get someone's attention. "Please watch" the store. is very similar to "Please look after" the store. "가게 점 봐주세요." 이나 "가게 점 지켜주세요." to "look" through the window implies a short time. 잠시 to "watch" through a window implies continuation 계속보는듯

Watch랑 look이랑 뭐가다름?

See는 안되는 건가요??

Yes, "see" is also a possible, and maybe even the most likely translation. It depends on the context or what idea or thought the writer is trying to convey. "Look" or "watch" conveys a sense of intent or purpose, while "see" may just happen without any effort by the 보는 사람. We don't get the context from the Duolingo sentence, so "We see through the window." is certainly correct, and the most literal translation.