There's got to be some relief in knowing Strange can at least target well with lightning. Less so when Billie can also tell he didn't take into account that lightning tends to set wood on fire, so, now the target is burning. That seems like the right metaphor for this entire conversation, to be honest.

"I sure hope you find making a new target as easy," she mentions in reply, watching the target currently on the tree smolder and crackle. That said, she waves towards where he's left the other throwing knives. "Toss me one of those. Like I tried to tell you, I can already do something like that, just not... like that. I don't actually throw magma around or whatever Epithymetikon's deal was. Just heat, and a whole lot of it."