The white mask is headwear that is found in the game files of Fallout: New Vegas, but was cut from the actual game. It seems to be a placeholder for the White Glove Society mask. The white mask is only obtained through the console commands.
Assaultron Helmet - Independent Fallout Wiki
The Devil's Pigtails - Independent Fallout Wiki
White Glove greeter, Fallout Wiki
File:Straw Scream Mask.webp - Independent Fallout Wiki
Security uniform, Fallout Wiki
Plan: Secret Service Helmet - Independent Fallout Wiki
Stealth suit Mk II, Fallout Wiki
Breathing mask, Fallout Wiki, Fandom powered by Wikia
White Mask Elden Ring Wiki