It may have something to do with copyright infringement, or unauthorized use.

The William Rimmer painting is "Evening (Fall of Day)" 1869-70. It was Crayon, Oil and Graphite on Canvas. It is not a picture of Lucifer but rather the Sun God Apollo falling as the Evening arrives. Some online sources have incorrect information that this was Lucifer, but they are wrong. Pictures of Lucifer with wings (that are not pro-Satan) typically portray Lucifer as falling with his back towards the ground and Michael the Arch Angel Driving him down with a spear. Rimmer looked back to classical Greek and Roman influences for his study of human anatomy, hence the God Apollo. The arm was altered to symolize the rise of the angelic figure rather than its fall. Perhaps there was also some copywrite reasons. But that is what I gather from all my sources.

I don’t believe this painting to be Apollo. The person depicted in this image lacks a gender, Apollo is distinctly male (even had a few male lovers). Lucifer on the other hand is an angel, and angels lack the ability to procreate because they are servants of the lord. Also Apollo is never portrayed with wings, just as a young male figure. Lucifer means “bringer of light” and the picture shows the bringer of light (the sun) descending into darkness. Angel’s greatest punishment is to be isolated from God, this causes great anguish, the figure in the painting is reaching for the sky in great pain as he falls into his enviable fate. The statue in Parque del Buen Retiro (shows the fall of Satan into darkness) shares almost exact similarity to this painting. This statue is one of a kind because it is the only public statue depicted of Lucifer. The statue is genderless, Hand is on forehead in agony, wings are spread, and the head is stretched back. And in no work of art is Apollo portrayed with these characteristics. Also if Rimmer did look back and gain influence from classic Greek art, I think the Apollo in this painting would have had some form of similarities to the original work. Also I can’t seem to find a comment from William Rimmer on this painting, I think its up to the viewer to decide.