Alex Eames from RasPi.tv has created and maintained a lovely “Family Photo” showing each iteration of the Raspberry Pi. The latest photo shows the Raspberry Pi Zero :
Clicking the photo will reveal a larger version. The photo shows a number of slightly rarer devices including the two red Chinese versions and a Limited Edition Blue Pi.
Source : http://raspi.tv/2015/raspberry-pi-zero-updated-pi-family-photo
Conditions of use : Alex is happy for the photo to be used provided the RasPi.TV credit stays intact. It is available at 1500px resolution as CC-BY-SA.