And the mask is ‘cause of the smell?
Possibly. Although the squid really don't have much of a smell when they are being grilled. That is a grill and its get a lot of smoke, from the charcoal and the bits that drip down and splatter from things cooking. But the masks are a very common feature of life here...Taiwan.
People wear them because of air pollution and the fear of getting an "infection" from other people. Almost everyone wears them while riding on their motorscooter and quite lot of people just always wear them when they go outside. Really common.
I do not wear one. Drives my wife up a wall. She wears one on her 'scooter.