Exaggerated view. From the residency ( foreground), the angle & sizes of the Imambara & Rumi darwaza cluster of buildings, was impossible even in 1859. And those large domes were never on the other side of the river ....

Agreed...but see Lawrence meeting the besieged, the man sitting beside a saddle, and extreme right a water carrier pouring water for a dying man....scenes that might have been witnessed and sketched by the artist or officers

Orientalist artist. Doubt that he was actually at the scene. Probably imagined this from the pictures published in Illustrated London News , The Graphic & other pictorial english press of the time. Some photos of these sites, a few years after the war, are more realistic ( see - http://www.merepix.com/2013/07/rare-photos-indian-sepoy-mutiny-rebellion-uprising-1857.html )

There is no mention of him ever visiting India.

The Indian Rebellion or Mutiny of 1857 changed public opinion in England, as it pondered the disaster that the loss of its richest colony would bring. I found some "Punch" cartoons from that year: http://www.victorianweb.org/periodicals/punch/51.html

...And that hairy (perhaps bactrian) camel from central asia with a dead arab in front of him - now where have we seen this before - Gerome ? Carl Haag ? some other orientalist ? ....lucknow in the doab - confused with constantinople & the silk route iconography ....