Not abstract art, but a technical drawing from an ancient treatise on siege machines by Biton. The catalogue says that this manuscript was copied in 1545, almost 1800 years after Biton wrote. Technical drawings have always been a problem in books on engineering, and they were even more so when the drawings had to be copied by hand by artists who had never seen what they were depicting. Some illustrations were copied from earlier ones, and others were reconstructions based on the text; I don’t know what category this picture falls into, but it is certainly striking. I suspect that it is supposed to depict a siege tower. You can find the catalogue and a drawing of a catapult from the same manuscript here.