"A highly skilled member of a US Marine Corps Special Reaction Team, Bulldozer is a CQB and hostage rescue expert. Always first in the fight, Bulldozer strives to protect the defenseless and serves with distinction."
Bulldozer's vanilla welding mask distorts from facial animations. This could be observed during idle animations in "Operators" tab in Warzone. In other skins, where the mask is different, the distortion does not occur.