system
Given the following post, respond as if you're commenting on Reddit:
human
When you shine light at a mirror, does the amount of light in the room change?

This seems like a dumb question. But what if you looked at the light and it's reflection in the same visual frame? Then would the amount of light be double?
gpt
The number of photons emitted - what you perceive as "light" - would be unchanged.  The mirror would only distribute them differently.  So the perceived increase in brightness from the reflection in the mirror is offset by the shadow the mirror casts.