Since this is a relatively new character, there has likely not been an established editorial protocol for when this character's eyes will "whiten" and when they won't.
Since Striker is a new mutant, with a fairly dynamic appearance and costume, they are probably still developing an editor's checklist for his power manifestations. When they get around to it it will look like a simple checklist to give to the artist and colorists.
When Striker uses his powers:
- If it is a minor manifestation, (hand or arm only) light flare at hand, eyes do not whiten.
- If it is a major manifestation, (requiring a full body interaction or both arms) flare both hands, whiten the eyes.
- for flight, at any level above hovering, whiten the eyes.
- for threatening an enemy, whiten the eyes, have lightning trail from them.
- For full out use of power, surround body with lightning, trail energy from eyes, whiten eyes.
Right now, they are probably still working out how the powers will manifest and we may see variations as different artists try different things.