die-in's are where they all fall to the ground to highlight what will happen if nothing is done about climate change.
really, it's not pointless - especially because it's on black friday. people are buying lots of goods for cheap prices without considering the impact on the climate so if shoppers saw this it could get them to consider the consequences of their shopping or make someone aware as surprisingly a lot of people still don't know about climate change - or drop a milkshake as you said lol. i think doing this on black friday is a great idea.
i guess i'm biased as i'm a strong advocate for climate action and take part in these events.