via Shorpy
Mademoiselle Fifi was the chat du John Moisant who flew the English Channel. She flew with him (and his mechanic), being the first cat to cross the Channel by plane, I understand.
He later died in a crash near New Orleans. From what I can tell, Mademoiselle Fifi is dressed up for the funeral. I haven’t been able to confirm this but it looks that way, anyway. What a lovely kitty kat!