North Yorkshire Police is appealing for witnesses and information after the theft at J’Adore on Church Street at around 3.15pm on Saturday, December 16.
The culprit stole two items from the shop and was pursued by the store manager on to Sandgate.
The offender then assaulted the store manager before returning the stolen items, police said.
A force spokesperson said: "We are conducting enquiries and are requesting the public’s assistance to help determine the full circumstances surrounding the incident and identify the suspect."
He is described as white, aged in his late 40s, around 5ft 11ins tall, with short dark messy hair. He was wearing dark Converse-style trainers, dark jeans and a dark leather-style jacket.
Anyone with information is asked to call 101 or email [email protected]
People can also call Crimestoppers anonymously on 0800 555 111.
Quote the North Yorkshire Police reference number 12170224753