Four Seasons Seoul was pretty much the same excellent service as usual. Associates and staff all wearing masks. Crowded with the start Korean domestic vacation period and biggest problem was the pool had no social distancing measures or capacity limits.
They gave some free surgical masks, alcohol wipes and a bottle of sanitizer under their FS cares program.
Andaz Seoul. Many hand sanitizer stations around the hotel. An "antivirus" plastic on all elevator surfaces and staff all wearing masks. Mandatory temperature check at check-in and COVID waiver had to be signed (stating had not been outside of the country 14 days prior). Some things had to give to pay for all the COVID related things, like, a severely degraded complimentary minibar and lesser quality ingredients for room service dishes. They went from Pellegrino to a local Korean sparkling water brand.
I don't think this plastic does anything considering they probably don't change it all the time.