Strange internal part after tearing down Pixel 7 Pro

Hi everyone, I recently went to a third-party repair shop to replace the broken screen on my Pixel 7 Pro. I paid for a so-called “original” screen the shop claimed to purchase for me, but the quality was obviously poor—there were thick black borders and the display looked worse than before.

I returned the next day to have the screen removed. During the screen removal, I took a photo of the internal structure of my phone and noticed a small piece of transparent plastic film above the sensors area.

I checked teardown images of Pixel 7 Pro on iFixit, and this plastic film doesn’t seem to be part of the original design. I also contacted Google official CS and they told me there shouldn't be a plastic film. This makes me wonder if the technician may have added or modified something during the first repair.

Would really appreciate any insight!

(The phone is closed now as I later bought an original screen myself and asked another shop to install it. New screen is ok. However, I just observed this plastic film when scrolling through my album. I feel confused why this area is different to the teardown image from iFixit.)