The Droste Effect is a special type of visual effect which is created when an image contains a smaller version of itself. These recursive images can potentially repeat infinitely, although they are ultimately limited by the resolution of the image, and they are considered a form of strange loop. A strange loop is a sort of self-referential paradox, in which one ends up back at the starting point after following a series of steps in a hierarchy.
This concept has been around in art for quite a long time, and at one point, it was known as mise en abyme; this term is still used in heraldry. The name “Droste Effect” was coined to reference a famous cocoa company's packaging, which featured a painting of a nurse holding a tray of cocoa, along with an image of the cocoa's package.
One way to create a version of the Droste Effect is to set up two mirrors so that they reflect each other. If you step in front of the mirrors, you will see yourself infinitely reflected, until the image of yourself gets too small to be discerned. Many people have noticed this version of the Droste Effect in cleverly mirrored bathrooms and bedrooms, and some people find it a bit unnerving and disorienting.
Famous works of art also include versions of the Droste Effect, such as paintings in which a mirror in the painting shows the image, or works of surrealist art which feature numerous duplications of an image inside of itself. It is also possible to create photomanipulations which demonstrate the Droste Effect.
At one time, the Droste Effect was very common on product packaging, and the next time you are at the market, you might want to look around for some examples. In product packaging which uses the Droste Effect, you can usually see a copy of the product package held by the person on the package, and in some cases, if you look closely, the replication of the product packaging features another replication.
Some people enjoy creating works of art which use the Droste Effect, and it can be a challenge to see how many copies of an image can fit inside an image. The smaller the copies get, the more challenging it is to create the replications.