With Kerrigan’s third prestige Desolate Queen, she gains access to the Heart of the Swarm ability Crushing Grip. However, the co-op or Void dependencies have modified the visual effects of the ability from their appearance in HotS, most likely done experimentally and left unfinished (as these changes were done in the editor before the introduction of the prestige system).
The version currently used in co-op does not resemble the version used in HotS, which had the affected units flail in the air while surrounded in a blue energy field. The version currently in co-op has no casting effect at all; it simply freezes the units mid-air and abruptly applies a pinkish glaze to them. The appearance is near-identical to the effect applied by her immobilization wave, which is liable to cause confusion. In addition, the effects no longer resemble the Crushing Grip icon.
The visual effects of Crushing Grip in coop should be returned to their Heart of the Swarm appearance, before they were experimentally modified and then left in that modified state.