DS3 is playing "construction" with two construction worker action figures, trucks, pattern blocks, and construction signs/barricades.
DS acts out construction worker 1 dreaming that the signs are animated and walking all over him while construction worker 2 sits by, oblivious. I ask what is happening and he says, "Construction worker 1 is having a nightmare."
He then acts out construction worker 1 being awake and having the signs pester him while construction worker 2 is, again, unaware. He animates construction worker 1 as freaking out. At my asking, he says, "This is what construction worker 2 sees," and he removes the signs and makes construction worker 1 act like he's freaking out.
Then he repeats construction worker 1 being bothered by the signs, only to have construction worker 2 start acting startled. I asked how construction worker 2 could see the signs, and he replied, "Construction worker 2 is having a nightmare about construction worker 1 being attacked by walking signs." When I asked if construction worker 1 could see that scene unfolding, he said, "No, he's asleep."
Finally, he animates the signs taking over vehicles and driving them away, while the construction workers are variously dreaming about each other dreaming a few iterations in. He comes over to me slyly and says, "The construction workers are stretching their amygdalas." (I suppose because they were afraid in their dreams.)
So, that's what construction play looks like here.