Incarnation Reflections

Incarnation reflections are a type of side effect brought on when a Time Lord looks directly into a mirror after their last regeneration. The effect causes them to see both past and potential future versions of themselves.

History
While the Doctor was wondering around the false reality house of Morlog, he encountered a bathroom and looked directly into the mirror. He saw a long haired version of himself he wasn't fond of before the First Doctor's face appeared, smiling back at him. After tweaking his facial muscles, the reflection turned back into a confused Doctor. Satisfied, he stepped away (The House of Morlog).