Pixie cut 1 is by Darxu on Deviant Art
Pixie cut 2 is by Derek Hetrick on Twitter
Mohawk 1 is by Ficeaxx (at least I think that's what the signature says) source is unknown
Mohawk 2 is by Little-Noko on Deviant Art
The key can be established by seeing which notes are played on the piano
Answer:
Hook and eye closures
Explanation:
You have to pull the closures apart one by one which takes a long time unlike the zipper and velcro.