Help With This Unusual Czech Cancellation/Overprint

This is Michel 174A from 1920. And here's what Google AI thinks about the additional element next to the circle/date cancellation. Is Google AI correct?

*** Edited by Staff - AI cut and paste removed per rules. ***

Sorry about that. Didn't know the rule. In a nutshell AI says that the design is a winged letter P that was applied to indicate official mail services, including transport. To me the design looks more like a winged anchor, so I'm hoping for more info here.