757's have a very high nose gear, to me they look "snobby" because their nose sticks up in the air a bit. Their fuselage is long and thin, adding to the snob appearance.

767s fuselage is much fatter, I liken it to a "cigar tube". It also sits lower to the ground than a 757, and of course, is a larger plane.

Now if you are curious about the difference between a 767 and a 777, the two biggest differences are that the tail cone in the back of a 777 is actually a "fin" shape, while a 767 is a cone. Also the 777 vertical tail is thinner and taller than a 767. The cockpit of a 777 is also fatter looking (if that makes any sense).