We provide a simple yet powerful demonstration of how an unobtrusive change to a graphical password interface can modify the distribution of user chosen passwords, and thus possibly the security it provides. The only change to the interface is how the background image is presented to the user in the password creation phase—we call the effect of this change the “presentation effect”. We demonstrate the presentation effect by performing a comparative user study of two groups using the same background image, where the image is presented in two different ways prior to password creation. Our results show a statistically different distribution of user’s graphical passwords, with no observed usability consequences.