The Evil Queen making a pass at Rumple also fits the pattern the show has developed of depicting evil women as more sexually aggressive: Zelena coerces Rumple, the Evil Queen made Graham her sex slave, “Dark Swan” Emma seriously put the moves on Hook.
The Evil Queen was fully half of Regina until basically a week ago.
When the Evil Queen appeared in Rumple’s shop, she came on to him in terms that were far more explicit than anything in The Brother’s Grimm.
So the sudden swordplay seemed like foreshadowing that Regina/The Evil Queen could be the masked swordsman who kills Emma in her visions.