I don't think this particular mirror is has dangerously sharp corners per se. If you look closely the mirror is 3-dimensional, meaning any "corner" would be like the corner of a kitchen countertop. Not that sharp. You don't have to clean it manually using cloth. Duster would do since it's not gonna have water stains, actual dirt, etc. of course, if you're still worried, you might check it out and survey in person at Harvey Norman.

P.s. Just found out these types of mirrors are bad FS. Personally, since the FS mirror rules only apply to actually using mirrors as a reflective surface to inspect your image with, I'd still want a mirror like this as a decorative feature. Mind over matter, eh?