This image is depicting the final tragedy nearly ending the play. In Act V Scene II, Desdemona dies after a struggle with Othello:
(Desdemona) A guiltless death I die,
(Emilia) O, who hath done this deed?
(Desdemona) Nobody. I myself. Farewell
Commend me to my kind lord. O farewell.
(Othello) Why? How should she be murdered?
(Emilia) Also, who knows?
(Othello) you heard her say herself, it was not I (AV SII, 150-157)
This point is very interesting. Othello doesn’t seem to be bothered more by the fact that his wife has died (!), than to argu that it wasn’t him.
Diving into the picture, you can see Desdemona lying dead on the bed, while Othello is clearly unhappy holding her hand. But, notice a very unusual thing, he isn’t looking at her, not even in her direction. He is looking so far, it is almost as if he looks at the person looking at the picture. Another detail worth mentioning, is that the lady next to him, most likely Emilia, is touching his head with a finger. To me, it feels like she is pointing at him (maybe too close) as if she is saying “It’s you!, you did it!!”. This point is reflecting the blame heavily weighing on Othello.
The connection to the play is evident, as the text shows, Emilia holds Othello responsible to Desdemona’s death, even though Emilia wasn’t there when it happened.. In the picture, just like in the text, she is pointing at Othello, holding him responsible.
Furthermore, you see the person far on the left, which is holding a knife (Iago to my understanding), after he stabbed Roderigo to death. It might be the knife that Othello is using later on to stab Iago, and ultimately himself, when he eventually kills himself and lays over the bed with his beloved wife, both dead, unfortunately. The amazing thing here is how many messages are conveyed through only one single picture.
Painting by William Salter of Othello weeping over Desdemona’s body. Oil on canvas, ca. 1857.
http://www.lib.umd.edu/binaries/content/gallery/public/artlibrary/shakespeare-in-art/othello/othellos_lamentation-_-painting-of-othello-weeping-over-desdemonas-body-by-william-salter-_-oil-on-canvas-ca-1857.jpg