It seems like your question is related to analyzing a specific image drawn by an artist, but I don't have access to images or context beyond what you've provided. However, if you're referring to a general method an artist may use when creating an image, one common step is establishing a composition or layout, which involves outlining basic shapes and forms before adding details.
If "two vanishing points on" refers to a perspective drawing, the artist likely used a two-point perspective technique, where parallel lines converge at two points on the horizon line.
If you provide more context or describe the image, I might be able to assist you further!