With so few drawings from Van Eyck still remaining, each one that exists today has been examined fairly rigorously in order to glean as much information about the artist's work in this medium as possible. It cannot be confirmed as to the purpose of this drawing - was it a study piece for a later painting, or simply an independant artwork in its own right? There remain many question marks around Van Eyck's career as a whole, mainly due to the many centuries that have passed since he first dominated Netherlandish art.
The artist would have spent a considerable amount of time on this piece, inserting large amounts of detail right across the scene. Many Renaissance drawings would leave large areas relatively untouched as a means to just concentrate on a specific element but in this case we see every inch of the panel has been carefully thought out and treated with importance. It is the architectural sketck work and the figure nearest in the foreground who initially grab one's attention, before we can then spot other figures dotted around the rest of the drawing.
This drawing featured a wide range of techniques and tools, including brushes strokes, a stylus, plus silverpoint, ink and oils. Each was used for a different purpose and would come and go in stages as he worked more detail into the artwork. The only real additions of colour are found in the background with some subtle touches of ultramarine which construct the sky. To use such a wide range of tools for this drawing suggests that the artwork held a great importance for Van Eyck and was most probably more than simply a supporting project to a later work.
The image found at the bottom of this page illustrates the work in far greater detail, allowing us to appreciate better the work that he put into the architectural structure of the tower. It was here that Saint Barbara is believed to have been imprisoned and later murdered, so according to religious teachings. Her sacrifice would ultimately gift her martyrdom after her recent religious conversion.
With so few drawings left from his career, it is particularly hard to draw too many conclusions from what we see in front of us. There is no general concensus or formula that we can fall back on, with so little to compare this drawing to. In some senses we are left with the only options of comparing it to his work in other mediums or drawings by other Netherlandish artists.