look at you!

to zdanie znaczy - tylko spójrz na siebie. jeżeli tak jest, to czy to jest poprawne gramatycznie, lepiej by było chyba look at yourself.

no chyba, że look at you, to jest (I) look at you

Poprawne.

look at you spoken
a.used for telling someone that you are not impressed by them, especially in reply to a comment that they have made about you or your behaviour:
Look at you! It’s eleven o’clock and you’re still in bed.

b.used for telling someone that you are surprised or impressed by them:
Look at you, all dressed up in a suit!