I am confused with the prepositions. Is it...
- looking at the mirror
- looking in the mirror
If you're looking in the mirror, you're looking at your reflection in it:
She was looking in the mirror at herself.
She didn't like what she saw in the mirror and broke it.
If you're looking at the mirror, then you're looking at the mirror itself (its frame, its surface etc.). In other words, you're looking at it, not at what's in it:
Come take a look at these items. Take a look at this mirror over here and these two beautiful chairs over there in the corner.
In would be used when you are looking at something in the mirror, i.e., you are looking at the reflection. For example:
He looked in the mirror to check out the haircut.
At would be used if you are looking at the mirror itself or the fixture around the mirror, e.g., the mirror frame or the quality of the glass, and not at the reflection. For example:
I was looking at this antique mirror yesterday. It would fit so well with our decor.
You can use all sorts of prepositions with "look" and "mirror." They have different shades of meaning.
You can look at a mirror, meaning you are looking at the mirror itself and not necessarily the reflection therein.
You can look in a mirror when you're shaving to make sure you didn't miss a spot.
You can look into a mirror, forgetting your surroundings and getting lost in the image.
You can look upon a mirror, which I believe implies you are not just looking but also contemplating the reflection. Although you might want to gaze upon it instead of look.
All of these are correct, but not necessarily appropriate for a specific context.