I'm in the same bridge. I get what's happening, but I don't get what, if any, the punchline is.

The deer have discovered a breach in our defences, France will soon be annexed.

I think the humor is in thinking one deer was like "holy shit, I've got to tell the others" and then giving a formal presentation where the other deer are also like "holy shit"

Its a green bridge like animal crossing to encourage wildlife to cross our infrastructure without getting run over.

Its pretty sad and depressing when you drive for 2 hours and see at least 2 deer and 1 hedgehog roadkills, where it can be reduced by just not only thinking about ourselves.

My read of this is: Deer and squirrels tend to run in front of moving cars*. The two species are distressed that something interrupted their ability to bolt into traffic.

*Where I live, obnoxiously and assertively so. The mule deer almost wait for cars to approach, run into the road, and then just stand there. Traffic-blocking protests have nothing on the deer.

My understanding: First deer discoveres a case when you can run over road unharmed. Teaches others, where they understand one can run safely over the road anywhere, thus the suprisement. Probably farfetched, but dank.