Twins: Portrait of an Artist?

This pencil drawing is an adaptation of a photograph of a famous artist.
Can you guess who?
I originally included other artists in the sketch, over working and spontaneous scribbles meant erasing the other figures. The combination of textures and smudges results in a mysterious scene. For example, the contrast of tones between the apparel, the face and the black tie.
The black smudge on the the textile background.
The image sits well with the poem:-

Twins.
Everything I have done, you have done.
Everywhere I have been, you have been.
Every word I have said, you have said.
Twins of different wombs, different minds, different worlds, different times.
How come you know so much about my life?
Can anyone write the next line?