The 26-year-old 'Bad Romance' singer posted the picture along with the caption: "I did it for u Terry. I'm sorry about ure mommy. She has princess die, but were all princess high."
The message contains a reference to GaGa's song 'Princess Die', inspired by the late Princess Diana.
Richardson, who collaborated with the star on a book comprised of photos taken behind the scenes during her 'Monster Ball' tour, spoke of his mother Annie Lomax's passing on his Tumblr, writing: "R.I.P. Annie Lomax, My Mom 1938-2012."
GaGa then showed fans on Twitter that she had only shaved a section from the back, revealing her hair positioned in a bun from the front, adding: "But we still have glamour in the front."