What to put above/on this mantelpiece?

[Olsihabi]

We've just redecorated and want to either put a mirror or new large picture above the mantelpiece, however the walls are very crumbly (old cottage) so anything heavy on the wall is a no no. I kind of have my heart set on a mirror but would this look weird if we just rested it on the mantelpiece?

The rest of the room is quite plain, apart from some colourful cushions and lampshade, so maybe a picture would look good but keep hankering after a mirror... anyone seen anything that might good? I'm going round in circles and can't decide

Now with photo

Definitely needs a mirror op. I think a round or oval one would look really nice.

I think it would need to be wall mounted though ideally.

I have a mirror that is self supporting:freestanding , with its base sitting on the mantelpiece.

Needs a mirror.

I think mirror too. If rectangular it should be the width of the fireplace opening. Resting on the mantel if definitely ok as long as secured at the top too. Traditional overmantel mirrors do rest on the mantel. Only caveat re mirror is if it would reflect something ugly don't do it e.g. in our kitchen a mirror over fireplace would just reflect cooker.