Original artwork, not a still
Will, changing the look not an idle threat with you.
— Buffy the Vampire Slayer ‧ 1997
Behind the line
What it means
Our interpretation.
Xander treats a change of appearance as a threat worth taking seriously. The joke lies in calling something as ordinary as changing a look an effective warning: with this particular person, he suggests, it would be more than empty talk.
Context reviewed
