These are the two versions of John Constable's Leaping Horse.
This is the sketch:
This is the finished painting:
If you click on each image, it will blow up for you. In real life the colors are more similar, but these are photos from different places on the internet. The first photo shows a rough look with rough looking clouds and tree branches, big swaths of color with little small detail, like an impressionist painting. In fact the idea is very similar to an impressionist painting. The second photo is much more specific and detailed, including tree branches, clouds, field in the distance, etc.
Both versions hang in major museums around the world, just never together. Usually it's the finished paintings you see in catalogues and books. The exhibition will be in LA next summer at the Huntington which owns one of the pictures.