This is a function of the transformer/MR16 LED interaction. Since the transformer must first turn on using the LED lamp current feedback, the lamp and transformer reacts to the dimmer bus voltage once the lamp is stable. A flash or flick can sometimes be observed if the lamp is turned on below approximately 50% intensity.
It was found that this is not a function of the dimmer brand or dimming method. If the transformer/MR16 LED lamps exhibits this characteristic, it will usually occur with any type of dimmer, whether leading edge, trailing edge, rotary or bell-press.