You would normally say 'You look confused', even though the action is temporary and immediate, which usually takes the -ing form. 'You're looking confused' is not wrong, it just doesn't sound quite right because it's not as often used.
You can say 'Are you looking for something ?' , or 'You're looking smart today', as well as 'You look smart today', or
' How do I look ? '
'Look(ing) ' is an irregular verb in this respect, and usage is idiosyncratic - it doesn't follow the rules, it's just a matter of customary use.