 		}
 
 		let now = NSDate().timeIntervalSinceReferenceDate
-		let cycle = (now / WigglePhaseDuration) + _phaseOffset
-		let phase = sin(cycle * M_PI)
+		let cycle = now / WigglePhaseDuration
+		let sign = (indexInCollection % 2 == 0) ? +1.0 : -1.0
+		let phase = sin(cycle * M_PI + _cycleOffset * M_PI ) * sign
 		let angle = CGFloat(phase * WiggleAngleMax)
 		let layer = self.layer
 		UIView.performWithoutAnimation { () -> Void in

			galleryCell.namesLabel.text = drawing.artistDisplayNames
			galleryCell.dateLabel.text = dateFormatter.stringFromDate(NSDate(timeIntervalSinceReferenceDate: drawing.date))
			galleryCell.deleteButtonVisible = self.editMode

			galleryCell.onLongPress = {
				[weak self]

			})
	}

	internal let _cycleOffset:NSTimeInterval = drand48() / 2
	internal var _phase:NSTimeInterval = 0
	internal var _wiggleAnimationDisplayLink:CADisplayLink?

