The later years of his career were dominated by self-portraits which were easy logistically to produce and also proved popular in the private art market around Amsterdam. There were around 80 self-portraits in total, which is certainly more than most artists have produced, though these were spread across several different mediums.
Rembrandt uses his trademark lighting techniques to apply focus to his own face, which in this case is themed as Zeuxis laughing. Perhaps having completed so many portraits of himself it was inevitable that he would seek to try new themes in order to keep his enthusiasm fresh.
The amusing tale behind this painting is clarified by the elderly lady who sneaks in from the left hand side of the composition. The story goes that antique painter Zeuxis would laugh himself to death after being commissioned to paint an old woman as the goddess of love. The cheeky grin Rembrandt displays in this self-portrait completes that representation.
This thought-proving piece can now be found at the Wallraf-Richartz-Museum & Fondation Corboud in Cologne for those looking to appreciate its full beauty in person. Naturally, art institutions regularly loan pieces between each other for exhibitions and so it is always advisable to check first before visiting if you are interested in seeing a specfic painting.
That said, the Wallraf-Richartz-Museum features a number of other significant artworks by the likes of Peter Paul Rubens, Jacob Jordaens, Frans Snyders and Antony van Dyck, Frans Hals, Gerard van Honthorst and Pieter de Hooch. There are also several other Rembrandt paintings in their impressive collection.