Rob, near Manchester, England, writes that someone had already attempted to correct this sign
…by sticking a bit of paper over the offending apostrophe; unfortunately it just drew attention to it.
Also, the name of the store is at the top of the sign is Booth’s, but the sign over the front door says “BOOTHS”.
Once you spot one, you spot more … inside the attached cafe, we had both “baked potato’s” and “baked potatoe’s”, “sachet’s of sauce”, “customer’s beware of fan” and several more spelling mistakes.
Presumably the same person does all the signs.