Answer:
an imaginary audience
Step-by-step explanation:
An imaginary audience -
It is the state of mind when the person believes and imagines about the people listening or watcher him or her , is known as the stage of imaginary audience .
The stage is very much common among the young teens and adults , people at this stage are very much active about imagination .
Hence , from the question , the Alex , imagine a lot about his new hair cut and overthink how others would react to his new hair style .