The airline uses on-brand characters to represent users during the seat selection step, which really enhances the entire process of doing something as mundane as booking a flight.
Design avatars that make sense — and be more inclusive in the process
Michelle Venetucci Harvey

The most interesting part of this experience to me is that: I’m actually paying attention to what avatars other passengers picked and thinking who they are, what personality they have, how they feel about this trip… The avatar is the representative of self-expression when you go through the process of picking the avatar for yourself. Therefore, it also builds and influences your perception about a person with a certain avatar.

p.s. This is still the №1 on my list of best UX.