Every time you beat all 15 puzzles in a single theme set, a new profile icon based off that theme will become available to you.

Unlockable	How to unlock
Baby Icon	Complete all 15 "Baby" themed puzzles.
Decorative	Icon Complete all 15 "Decoration" themed puzzles.
Female Icon	Complete all 15 "Fashion" themed puzzles.
Horror Icon	Complete all 15 "Horror" themed puzzles.
Love-struck Icon	Complete all 15 "Love" themed puzzles.
Medieval Icon	Complete all 15 "Medieval" themed puzzles.
Pirate Icon	Complete all 15 "Pirate" themed puzzles.
Science-fiction Icon	Complete all 15 "Science-fiction" themed puzzles.