Runescythe9852 said:

What is with that pink line on her hand?

I think that A: there's more to the background that was cropped out of the pic for whatever reason, and that line is supposed to be something that was/is in her hands, though the source doesn't mention a full version elsewhere.

and B: that the pic looks a lot more like Stoopix' work than it does Twinkles, but she's got a pretty classic Twinkle mouth so maybe one of them did lines and one did colors.