is bleach episode 12 filler?

Staring down Uryū Ishida in an alleyway in Karakura Town with Kon kneeling behind him in his body, Ichigo Kurosaki tells Uryū to explain the rules of this duel to him. However, Uryū merely takes a piece of Hollow Bait out of his shirt pocket and reveals that they will be using this, prompting a confused Ichigo to ask him what it is.

Uryū explains that it is bait for Hollows which will attract them if crushed and scattered into the air, shocking Ichigo.