[i] Since walking between regions in Mirrorlands is nearly impossible, everybody has to choose their own means of transportation. Wings are quite popular because they are very cool and many people dream of being able to fly. Which, of course, doesn't automatically turn anybody into an angel, but you can't stop the stereotypes...
Other ways to move around include teleportation, which is what Matt was using before. However, there was a catch: in order to move to a new place he needed to see it clearly in his head, or in his thoughts hold onto some kind of landmark or a person who would be there.
It proved to be difficult in many situations. Imagine if you needed to contact a person who lived next door and you had never seen them before or visited their place. So, to do that you use a drone to hover outside of their apartment and take a picture, then you connect to the internet, find their IP, transfer yourself over the Wi-Fi, re-assemble, and hope that you won't end up merged with their furniture because you got the positioning slightly wrong in your head. All of this as opposed to, you know, just walking outside and knocking on their door. Sure, taking the risk to teleport could be necessary in some situations, and absolutely handy if you're a thief. But most of the time it's too over the top and drains the user's energy.
Picking wings has always been a very personal process. Matt decided on his wings shortly after the spiral place was discovered and tested them there. If you're curious to see what his flyers look like, take a peek here.