Order vs. Disorder: Ms. Shears is arranging the paints and jars in order by each of their heights. This scene portrays order which Christopher is very fond of.
There's a whole bunch of letters from mom with kind words inside. She loves me!
Communication: Ms. Shears is yelling at Christopher when he was holding Wellington's dead body. Christopher becomes frightened and doesn't understand why she is yelling.
Trust: Christopher wants everybody to be honest and not lie. He believes that if someone lies, they will go to jail because it is a "crime" in his eyes.
Stars are great, I love stars and space! I need to keep calm.
Love: Christopher finds letters from his mother and realizes that she loves and cares about him and not dead as his father had told him.
Betrayal/Deceit: Christopher believes his mom is dead, but finds letters that were written after her "death". He feels his father has lied to him and he feels betrayed, so he goes into shock.
Logic vs. Emotion: Christopher feels afraid about getting arrested, so in order to calm himself down, he think about space and stars which he enjoys very much. This isn't very logical but it helps him emotionally.