Day 6 of Dalek Week!
This is supposed to be how Alek keeps on telling himself that he and Deryn can never be, because he's a prince and she's a commoner, blah blah blah. And yet he can't stop thinking about her, and it's bothering him. Because Alek is a little clueless when it comes to relationships.
The fact that Deryn has wings is the fact that it's kind of Alek's imagination, rather than her just hanging his over his head being half bird. It's representing her air-ness and whatnot, and the fact that Alek likes her and pictures her as some sort of unreal force.
Deryn and Alek belong to Scott Westerfeld. Happy viewing!