So, the iMac is not hermetically sealed. I was using my flashlight to explore fingerprints and smudges on the screen so that I may wipe them off as I’m prone to do every now and then when I discovered, what I thought, was a scratch. I thought to myself “how could that be? I’ve never used anything abrasive against the screen”. Upon further investigation, I realized that it was not a scratch, but a piece of lint. Shortly thereafter, and more exploration, I noticed more lint strewn throughout the top of the glass. So, therefore, the glass is not sealed well enough to the frame by the magnets like I supposed it would be. I understand that the glass is indeed removable so it couldn’t technically be hermetically sealed, however, I don’t like lint getting in there either.