It happened on Saturday at The Meat Trade Counter in Commercial Way, Oakengates.
West Mercia Police said CCTV of the incident shows what appears to be a man looking up a woman's dress.
Officers are keen to speak to a man in the area at the time who they believe could help with inquiries.
He is described as black, with hair tied back in a ponytail or bun and wearing a black top with "TEAM" written in orange on the front and "STADIUM TOUR" written on the arm.
Anyone with information can contact West Mercia Police on 101 or at westmercia.police.uk, quoting incident reference number 00375_I of September 26, 2020.
Alternatively, contact Crimestoppers anonymously on 0800555111 or crimestoppers-uk.org