Thing 2 has a tendency toward drama. If she's going to be upset about something, she can be VERY upset about it. Thing 1 tends to internalize a lot of things, but Thing 2 projects her emotions.
There was a particular time when Thing 2 was in preschool. One day when I came to pick her up, there was some drama at the door from another kid. For a birthday favor, one of the kids had passed out some rather cute foamy masks of different farm animals. They looked something like, but not exactly like, this:
I seem to remember a chicken and a cow, I know it was a set of farm animals. There must have been three or four of each animal. The problem was that one little girl was offended that she'd gotten a pig mask. She didn't want to be a pig, pigs are dirty and fat and stinky. She wanted to be a kitty or a puppy. That was the only thing she'd be happy with. She was crying and carrying on, and I was very proud when the teacher didn't just give in and trade out the little whiner's pig for someone else's kitty. So the girl's parent carried her off screaming and crying about her pig mask.
I entered the room not quite knowing if I was going to have to carry out my own child in a melt down.
I found Thing 2 by her coat cubbie. With a huge smile on her face, she told me she had a mask. She put it on, it was a pig. She started to snort and grunt. Her snorting made her laugh. She laughed so hard she could hardly walk. She laughed and laughed and snorted and snorted, and would catch a look at herself in a window and then laugh some more. Of course I was laughing at her too... All the way to the car she was snorting and laughing, and stopping to snort and laugh some more.
If she's upset about something, no on cries harder. At a playdate recently the mother hosting told me she thought a trip to the hospital was in order based on Thing 2's cries, but it turned out there wasn't actually an injury, the tears stopped and everything was fine.
But if she's happy... She finds humor all around her. She watches her environment, sort of scouting for something funny to happen, and will point it out and giggle about it with you. She is the one who mis-hears things, in a completely ridiculous way, and then giggles about it. Stuff like that is really common.
I just can't get that scene out of my head... Thing 2 in her pig mask, snorting and laughing so hard she snorted, then laughing and snorting some more.