Maybe the TUI logo isn't
quite as meaningless as you think!
The weird smile thingy is actually made up of the three letters T, U and I if you look carefully. From one perspective, the smile is the T, looking at it 'normally' looks like a U, and the eye is the dot of the I.
Don't ask me where this pointless information came from! I think I read it in a German TUI brochure when the new image was first rolled out!