West Yorkshire police said it happened on Tuesday, March 18th, just after 1:20pm.
A spokesman for the squad said the woman walked to a store on White Abbey Road near the intersection with City Road, then pulled out a knife and asked for money.
A West Yorkshire police spokesman said: “When the suspect was told they had no money, she snatched her cell phone from the hands of the female victim before leaving the store.
“The Bradford CID detective wants to help identify the woman portrayed.
“People with information will be asked to contact West Yorkshire Police by calling 101 or online at www.westyrkshire.police.uk/livechat.
“Or alternatively, call independent charity Crimestoppers on 0800 555 111 anonymously.”