The feet are too big.

Looks like she's higher up the stairs

It is. If you look at the cheekbones and where their hand is, it's the same person. The higher person just has their hair in a bun.

Also the stairs railings are farther apart in the mirror.

Or, it's a different perspective and the photo is just out of frame. She's standing close to the banister, the photo is on the other side of the staircase on the wall.

That's what I though at first too, but you have to take into account the height at which the mirror is mounted, and the fact that the mirror is not mounted directly opposite the stairs. The reflection is showing the guy further up the stairs, but at the angle the picture is taken with how it bounces back light, you just can't see the guy at the bottom of the stairs reflected. I imagine that if you were to take a picture on the other side of the room you would see both guys in the mirror.

They look like orderlies from a dementia ward

Yeah! Maybe too many teeth.

Sweet Tooth is better than this guy and that's saying something