During the assault on the X-Mansion Colonel William Stryker meets Wolverine and says '...me on the other hand, nature.' while his face looks weird and distorted and it appears as if he's done something to himself. He proceeds to correct the distortion with an adjustment of the cheek and looks slightly more normal. Has he done something to himself or is this simply a cinematic effect?
This is a very brief moment, almost of a few frames which could be missed if not carefully looked at.
This GIF might clarify a little bit more: