This is what emerges when you recursively feed noise to a artificial neural network trained to recognise places (e.g. you give it an image and the response is something like 90% beach , 20% desert, 2% swimming pool). The familiar shapes you see floating past is abstractions the network has made for the different categories. Some categories feature more prominently because the amount of images used to train them differ. For example the ""fountain"" category contains 111,496 images compared to only 883 in the ""nuclear_power_plant"" one. So that's why you see a lot more fountain like shapes than big chimneys.
