The tutorial puzzles were absolutely trivial, but I spent a decent amount of time trying to understand the mechanics of the main puzzle and frequently actions produce unexpected results. I do not understand why sometimes only a piece is mirrored, and then sometimes the whole puzzle is, or why tapping can prevent some pieces from being flipped, etc. I do not know if it is buggy or just confusing.

EDIT: I see. Drawing a line causes a mirroring effect at a line perpendicular to the one drawn, located at the furthest point in the direction of the drawn line.