What is this part and where does it go?

Hello. This is my first Ifixit question.

I was replacing my WX220's screen by following the guide here when this part fell out of nowhere. Now the thing is, i have scanned all the guides here and nowhere can I find this part. I took several pics at every step of the disassembly and the part is not visible.

Please help. I dont wanna close the camera without putting this part back where it belongs.