I think the size id fine but I would choose a piece of art instead of a mirror.

Oh wow. I'm trying to decide what is battling it out more with that front door .... that mirror or that floor rug. That does not look good at all. Remove the mirror and hang art. Remove the teal bench cushion, that matches with nothing, and replace with something more neutral. And then replace that area rug with something that matches the style of your front door and home. Something way less bold and busy and dark.

I think the mirror looks fabulous and I like the teal color underneath. I would perhaps suggest a slightly larger more substantial bench, however, as it looks a little small under that large mirror. I like how the mirror reflects the pattern of the front door too.

I agree that a mirror by a front door is a useful placement.