Unknown mark on a Sheffield Biscuit Box.

I have a Biscuit Box of Sheffield Silverplate by Atkin Brothers. It is marked with their initials and ESPN (which means it is after 1896). My question is about an additional mark of a hand with a pointing index finger on the bottom of the box. I have been unable to photograph it as of yet as it is VERY small. Does anyone know what that mark indicates? Any information will be appreciated. Thanks in advance.