The offence took place between 7.25pm and 7.45pm on Monday on East Parade.
The man pictured the e-fit image is described as white, around 6ft and in his late 20s.
He is slim and was wearing a dark hooded top and dark trousers.
Anyone who recognises him or saw anyone acting suspiciously in the East Parade area is asked to call North Yorkshire Police on 101, select option 2 and ask for the Harrogate Investigation Hub.
Please quote 12170047318 when passing on information.