Artist's comments suggest that 'minor' in this case refers to Quon as a minor character in RahXephon which makes her difficult to recognize.
Artist Comment: 久遠かわいいよ久遠。ちょっとマイナーなんですけど、大好きなキャラなので・・・
"Quon you're so cute. She's a bit of a minor character but I really like her so..."
Lala?
As appropriate to the musical theme of RahXephon, Quon says "lala" instead of the usual "ara" when something unexpected happens.
The artist is making a joke on Lalah Sune's name here.You're minor, so you wouldn't get it!