Hi Rui,
The clue to this puzzle is the mirror image of the pendant of Claire.
Mirror image is an expression that means that what you see is the reverse of what is in front of you - right and left is reversed as it would appear if seen in a mirror.
You do not actually need a mirror to use but to look/remember what Claire's pendant look like. Then think of the geometric shapes in reverse position just like when you place the pendant in front of a mirror.
This reversed position of the geometric shapes is what you enter as the door code.

Good luck,
MaG