The last time she tried to offer Fluttershy's brother a small job to get him back on his hooves, Rarity was rewarded with a trashed boutique and a dreadful cleaning bill for her cat. For most ponies, an encounter like that would lead them to tossing out Zephyr Breeze the instant he tried to come back for another shot.
However, due to his recently-acquired confidence, as well as his sister's approval of his new behavior, Rarity hesitantly decided to give him a second chance after he was fired from his most recent hairdressing job. After all, one of the most important foundations of friendship is forgiveness; plus, the fashionista was meaning to look for a stylist for an upcoming fashion show she was running.
However, a small snag may be enough to put both Rarity and Zephyr Breeze through a rather awkward loop. Since the mare can't exactly get a fair reference from Zephyr's previous employer, she would have to see his skills by example. But since all of her wigs were gone, that meant there was only way she could know how good of a hairdresser he was: By having him cut somepony's mane.
And Rarity was the only pony around.
[Note: This story is my entry for the Make Rarity Not Garbage contest, hosted by the Barcast group.