The police do not have unlimited power to order us around.
Quote from a lawyer in the article:
> Personal delivery devices must yield to other pedestrians and pedalcyclists in a pedestrian area
Sounds like the robot legally had to yield to her. If so, what lawful basis would the officer have had to make the order?
Just because something must yield to you doesn't mean you have an infinite right to obstruct it.
It's quite possible (and likely!) for you simultaneously to have an obligation to yield and the other party to have an obligation to not block.
The article includes "she might spend 10 or 15 minutes blocking it, moving as it does, to delay it on its journey".
That sounds like the robot tried to yield and she purposefully moved to counter that.
That would likely support a charge for obstructing traffic or disorderly conduct or something similar.