The rollover text (for those who insist it’s an integral part of each XKCD cartoon) was “3D graphs that don’t contact the plane in the closure area may proceed as scheduled, but be alert for possible collisions with 2D graph lines that reach the hole and unexpectedly enter the 3D space.”
Is the therapist playing off an ambiguity to humorously chide the client for being late … again?
Sources say that either the exclamation “Great Scott” is not attached to any particular person with that name; or else may be associated with Sir Walter Scott, or with U.S. General Winfield Scott. But here, with the talk of Antarctica and the South Pole, surely they intend some kind of glance at famous and unfortunate polar explorer Robert F Scott?
And another from Andréa, who calls this “Barely an oy”. Also fodder for you dialectologists out there.
I find the hovertext even more confusing than the cartoon itself: “The only other person to walk by was a linguist back in the ‘80s, but she just spent a while directing the phrase ‘help me down’ before getting distracted by a squirrel and wandering off.”
(Edit: the hovertext actually says “dissecting,” not “directing.” So that’s much less confusing.)