Only the person that has access to that respective wallet can view the seedphrase within MetaMask. So keep your Secret Recovery Phrase safe and be careful what websites, dapps and people you interact with.
I would say that if you share your screen while revealing the seed phrase, the one you share your screen with, will also be able to see your seed phrase. I guess it is possible for a hacker to see your screen using malware, RAT or some other tool on your computer.