Baily saw a bright orange sweater while shopping and thought it was ugly. then baily starts to see more and more people wearing the orange sweaters, which makes her like the sweater more and eventually buy one herself. this situation is an example of

I believe the answer is: Familiarity

In this context, familiarity refers to psychological phenomenon that cause people to develop preference toward a certain thing because they see it often.

This happen when people experience repeated exposure toward things and started to develop interest/attraction toward that thing.