Named such because like many of the roles Aaron Eckhart plays, it seems like a nice drink but fucks you up later. Just like Aaron Eckhart often plays a role where he seems like a nice guy, but fucks you up later.
"I Shouldn't have had that last Aaron Eckhart last night. I did not expect the results."
"Man, that Aaron Eckhart was just like Two-Face. Two-faced."