If you understand this joke, please let me in on it. When I first drew this, it made perfect sense to me. Now I can’t remember exactly what it was that made perfect sense!
Er... I for one don't get it.
Unless there's a mirror or something reflective, Megan can't see whether Candace sports a smile or a frown, so Megan is saying that in reaction to Candace saying... nothing? And Candace's answer also makes no sense to me.
So, sorry, can't help.
I think the joke is that Megan doesn't know whether Candace accepting her as a friend is a sign that she's a good person, or whether the fact that Candace accepts bad people like herself as friends means she isn't a good person either.
It reminds me of the old Groucho Marx line: "I refuse to belong to any club that would have me as a member."