You might already have known about Amabie, yokai was seen in Edo period. (See in detail)
I’ve checked famous free illustration shop and I’m amazed to find several different pose of Amabie. This shows she wear mask.
This site makes new illustration at the request of consumers and now he only accepts related to corona virus(COVID-19). That’s why this illustration requested by somebody…
Why yokai wears mask? From what, she protects her?
Probably, this picture means only “Amabie with mask”. So I feel Japanese don’t care about what’s the origin and have improved (or modified) new style. It’s so funny for me as a Japanese!!
It is said that she said “people take her portrait evacuated from epidemic”. uh,,, Amabie with mask seems to be something weaker. Gives me some different as God wears mask.
BUT, definitely this is cute, so it’s OK!?