Renoir: Lise Sewing, 1876
Artist: Pierre-Auguste Renoir French, 1841 - 1919
Dimensions: Overall: 22 x 18 in. (55.88 x 45.72 cm) Framed dimensions: 7 25/32 x 27 5/8 x 3 in. (19.764 x 70.17 x 7.62 cm)
Medium: Oil on canvas
Credit Line: Dallas Museum of Art, The Wendy and Emery Reves Collection
Style: Impressionism.
Pierre-Auguste Renoir met Lise Tréhot in the spring of 1886, when he painted in and around the Forest of Fontainebleau with Jules Le Coeur and Alfred Sisley. Source: Dallas Museum of Art

Golden rectangle
A golden rectangle is a rectangle whose side lengths are in the golden ratio, one-to-phi, that is, approximately 1:1.618. A distinctive feature of this shape is that when a square section is removed, the remainder is another golden rectangle, that is, with the same proportions as the first. Square removal can be repeated infinitely, which leads to an approximation of the golden or Fibonacci spiral.

Droste Effect
The Droste effect is a specific kind of recursive picture, one that in heraldry is termed mise en abyme. An image exhibiting the Droste effect depicts a smaller version of itself in a place where a similar picture would realistically be expected to appear. This smaller version then depicts an even smaller version of itself in the same place, and so on. Only in theory could this go on forever; practically, it continues only as long as the resolution of the picture allows, which is relatively short, since each iteration geometrically reduces the picture's size. It is a visual example of a strange loop, a self-referential system of instancing which is the cornerstone of fractal geometry. Source: Wikipedia, Droste Effect.