Via: The PreSurfer
The Droste effect is a specific kind of recursive picture. 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.
The effect is named after a particular image from a 1904 campaign that appeared on the tins and boxes of Netherlands Droste cocoa powder. Here are some other examples of the Droste Effect in packaging, featuring Land O’ Lakes Butter, Cracker Jacks and Morton Salt.