[raptor99]

Wearing costumes establishes costumes and illustrates the joviality of at least a portion of the attendees of the event. It would be odd to say that it is immaterial that you went to a concert or a restaurant or any place really, and lots of people were dressed as Vikings, or as SWAT, etc.

[woodruffw]

It's immaterial insofar as the US Capitol is not, in fact, a concert or restaurant.

(And similarly, it should be clear that an insurrection's nature doesn't depend on whether the crowd is jovial or not.)

[fireflash38]

It was a happy guillotine. The French are also off the hook because they were so damn happy to be guillotining people.