It's definitely more to do with the feet that go in.them I think. Saltwaters are foul, and look like a 4 yr old would wear them, yet the pic above with the white ones does make them look OK.
I've never seen Birkenstocks look good on anyone though. The people in them tend to also be in tie-die and be on their way to Glastonbury with a tent mind you.
I don't like the eyelets on the Tu ones, but Saltwater and Birkies would be further down the style chain for me.