I'm inclined to agree with whoever sent this one in. I might not have put it in quite such absolute terms (certainly not with so many exclamation points), but
'You look good' is certainly the primary sense of 'Sie sehen gut aus,' so it's definitely misleading to omit it if the phrase is in there at all. And it probably would indeed be helpful to include both the above entries in order to clarify the difference in English. (It might even help some clueless native speakers.)
However, unlike Claudia F., I don't think anyone needs separate entries for 'du' and 'Sie' every time the word 'you' appears; just pick one.
BTW there are some other really dubious entries under 'you look' as well:Dictionary: you look
'Look you!' is to the best of my knowledge archaic, or at best BE.
I don't think anyone needs the sentence 'You look disheveled' as long as the adjective 'disheveled' is in there. However, 'dishevelled' should be marked [Brit.] and 'disheveled' [Amer.], and both spellings should be keyed to both 'zerzaust' and 'zerrauft.'
I'm also not convinced that anyone needs the sentence 'Did you look at yourself in the mirror?', much less the same sentence with 'glass.' (Isn't '(looking) glass' in this sense largely archaic anyway? Snow White and Alice in Wonderland each had a looking glass, but that was then...)