Apple tells Wirecutter that the HomePod’s base can indeed leave residue on certain wood countertops, as reviewers and owners (such as Pocket-lint, and folks on Twitter) have noticed.
Apple says “the marks can improve over several days after the speaker is removed from the wood surface. “If they don’t fade on their own, you can basically just go refinish the furniture—the exact advice Apple gave in an email to Wirecutter was to “try cleaning the surface with the manufacturer’s suggested oiling method.”
In other testing, Wirecutter says it’s seen no visible damage when using it on “glass, granite countertop, nice MDF, polyurethane-sealed wood, and cheap IKEA bookcases.”