FYI iMac 21.5" Display adhesive strips need a slight alteration!
It looks like the newer 2017 models have moved the front facing microphone from the top of the display to the bottom off to the right side. A small cutout for the microphone will be needed.
Warren Wilson posting here: Muffled Microphone - iMac 21.5" (mid 2017) - Following Adhesive Strips Has a good image of the new placement.
Can you also make the correction in the guides as needed?
Is this a good question?