Partially Sighted?

It seemed a polite thing to do at the time. The woman in front of me at the check-out was struggling as she tried to keep hold of her white stick under her left arm whilst trying to arrange her shopping from her trolley onto the conveyor. 'Would you like me to help?' I offered and proceeded to stack up her shopping for her, providing a commentary the while as to what I was doing so she would know.

As it became her turn at the till I was quite surprised that she suddenly needed no further help. Indeed she took the liberty of handing over her white stick to the assistant and, thus revealed, I could see that the far end of the white plastic stick was a mop-head for which she then paid. She gave me a cheery wave as she left, clearly convinced that she had escaped the clutches of another of Nailsea's garrulous nutters.

Who is the partially sighted one now?