It's extremely modular and simple and extensible. It's a collecting of small libaries that makes generating arbitrary vector graphics extremely fun. You have a base SVG layer and on top you have a charting library, 3D models and other stuff. It also comes with a ton of cool math mini libraries. If something is missing it's very easy to write your own.
All the pieces are very decoupled and in pure Clojure (unlike a lot of the heavier scicloj stuff that's being use nowadays)