Opposite and in front of

[JaneGothic]

People say:
Sit in front of the TV
Stand in front of the mirror

But in the picture I attached it's opposite. As far as I know, we use opposite when the objects are separated by something (e.g. road, river, some big space).

Opposite is used to say the person or object being referred to is located at the other end, side, or corner of something else. But in the examples with the mirror and the TV they are at the other ends as well

 

[jutfrank]

She's standing in front of the mirror, adjusting her hair.
She sits in front of the TV for hours on end.
She stood in front of the painting, aghast.

In each case, the object (mirror, TV, painting) has a 'user interface' that we can call a 'front' and which is designed for human interaction, so there's a functional relationship between the person and the object.

The preposition 'opposite', though it is used to describe things facing each other, doesn't have this functional relationship. The main idea with 'opposite' is that there's some space between the two things, which is not important in the examples above.