They're giving out free stuff in there! Marisa doesn't know how to use a library and assumes its just a free book store.
The audio was from famous youtuber Jontron's "Barbie Games" video. (Warning: That video contains humor not suitable for young.) Marisa is from Touhou Project. The footstep sound used is a cut off piece of Foxy's Running sound from the first Five Nights at Freddy's.
