The painting (bottom image) is The Night Watch, by Rembrandt van Rijn, 1642, Oil on canvas, 142.9"×172.0", located in the Rijksmuseum, Amsterdam.
The top image is a 17th century copy with indication of the areas cut down in 1715.
According to Wiki:
In 1715, upon its removal from the Kloveniersdoelen to the Amsterdam Town Hall, the painting was trimmed on all four sides. This was done, presumably, to fit the painting between two columns and was an all-too-common practice before the 19th century. This alteration resulted in the loss of two characters on the left side of the painting, the top of the arch, the balustrade, and the edge of the step. This balustrade and step were key visual tools used by Rembrandt to give the painting a forward motion. A 17th-century copy of the painting by Gerrit Lundens at the National Gallery, London shows the original composition.
I discovered this Art Fact That Makes You go Huh?!!! while researching for a previous blog post, Tableau Vivant. Enjoy!