Apart from reading, you need to be spending time looking at relevant images. Yes, this is valid work. In order to write good essays for this course, you need to begin to develop the skill of visual analysis.

The best way to do this is to find good books full of pictures (it doesn't matter if the text is rubbish - coffee table books on art history will do). Find a comfortable place to sit and spend time looking at images that are relevant to your essays. Get to know all of the details and become familiar with images.