Clearly visible, not hidden.
Easy to see.
Caveat; you may have to be looking from the right angle and/or be able to see beyond the obvious. Just because it may
be hard for you to see it doesn't mean it isn't in plain sight.
When I first walked in the
doorway I couldn't see much of the room, but as
I moved deeper into the room I saw the
artwork hanging on the wall in plain sight where anyone would see it.