As the sentence which followed made clear, it's doing this in front of a horde of witnesses (which in this day and age invariably includes people armed with cell phone cameras, video recorders, etc.) that police officers wouldn't be inclined to do. Sure, there are police officers all over the place who do things when they think they aren't being watched or recorded by anyone who would report them. But that clearly wasn't the case here.
you can't 'splain this photo away ...
The best lib/socialist spinner couldn't spin this one as 'professional' officers of the law