Unfortunately Brockbank’s caption for the picture doesn’t provide much in the way of context.
Perhaps it could have provided an explanation for why the Emperor appears older and more decrepit than ever despite the cloning process.
As for what’s in the vat… might that not be a container for the production of Snokes?
It was confirmed via the novelization of Star Wars: The Rise Of Skywalker earlier this year that the Emperor Palpatine we see in the film is actually a clone of the character from the original trilogy, so is it possible that what we’re seeing in this concept art is linked to that?