Arnold Genthe was a German photographer, he worked at New York portrait studio. He used an unobtrusive camera and would not tell the subject when he was going to make the exposure.
Genthe photographed many famous personalities of his era including Sarah Bernhardt, Jack London, Anna Pavlova and Sir Arthur Conan Doyle, even Theodore Roosevelt and Woodrow Wilson.
Genthe had a cat named Buzzer and he photographed his cat along with his subjects as a prop to put them at ease and produce more natural, unposed images. It seems there were in fact four “Buzzers” over the years, explaining the feline’s apparent longevity.