A portrait sketch by Tarragon. An easel painting in oils is not a light undertaking. It takes time and effort, of course, but also requires space for longstanding messiness. Oil does not dry swiftly. Nor is the rather factory-like perfume it exudes the sort of thing you want to keep in your kitchen.
Which is why Tarragon, like most painters in oils, makes small sketches in order to plan out larger paintings. That way you can be confident of the composition before breaking out the big guns.