We have a lovely Ikea mirror in our lounge. It was hung on the wall above the sideboard. The sideboard has since been moved to the other side of the room but the mirror remained where it was. It’s now just sort of hanging there. In-between the settee and dining table, it looks odd, it’s not even central iukwim.
It would look much better moved across to the other side of the room, either above the sideboard or above the electric fire. DH is reluctant to move it because it was a ball ache to hang & it means more drilling holes again & filling the hole where it’s been.
I think a mirror does need to be hung above something, it looks odd just hung there with nothing underneath it!