Is possible to set what mirror should to show? not the rest of the interior/ area only something different?
The mirror shader doesn’t have any specific settings to do this, but you could apply a texture to the wall behind the mirror to get the reflection image you want, and adjust the mirror glass to minimize reflection and maximize transparency.
A quick example:
This just uses a screen shot of the preview for this view for the reflection, so the quality of the reflection is low, but it conveys the general idea. I think the hard part would be getting the view angle and lighting in the reflection right to be convincing.
Photoshop, my friend 