She's either contemplating about her past memories and experiences, or someone that they held dear to themselves, that they wish to be with again... maybe forever...
Or maybe I'm thinking too much and she really is just thinking about nachos, though the question is, what kind?

Whatever she's thinking, I feel the urge to hug her. But hesitate for obvious reasons.

Very calming!

This character oftenly got depressingly sexy after awhile ;-;

If only my deep thoughts went that deep. I usually have to get smashed to get that deep. Fortunately, I'm a lightweight. :D