5301991f_and_The_Art_of_Breaking_Things__detailed_explanation
[signal] Chewing pen or pencil [part of body] mouth [possible meaning(s)] self-comforting [detailed explanation] 
Like smoking and infant thumb sucking. The pen is the teat. Remember that next time you chew the end of your pen…
“I pretty much try to stay in a constant state of confusion just because of the expression it leaves on my face.” – Johnny Depp | Zen and The Art of Breaking Things
detailed explanation