Looks like BOL or BOU.
Bolton or Bournemouth,though Bournemouth wouldn't fit if the size of the BO was maintained for the whole name.
Note the Bata shoe shop on the right, orignally Czech made then made in England, we didn't have Bata shoe shops in London. Bata shoe factory was in East Tilbury, Essex.
If they're West Ham supporters it could also be the BOL of Boleyn.