But he spat at her before punching her in the face and kicking her a number of times as she collapsed on the ground.
The woman was taken to hospital with concussion.
Officers believe the man in the image may have information which could help their investigation.
British Transport Police want anyone who recognises him or has information to contact them by texting 61016 or calling 0800 40 50 40, quoting reference 142 of 22/02/21.
Alternatively, the can call Crimestoppers anonymously on 0800 555 111.