A button, in particular, a stop request button for a public transport vehicle, comprises a body having means for connecting to a holding tube and interaction means controlling the modification of the state of an electrical signal. The body defines a hollow volume opening out through an external window. A display screen is disposed in the hollow volume, and an optical plate is positioned between the screen and the opening of the body. The optical plate forms a floating representation of the image displayed by the display screen in a direction of observation perpendicular to the external window. The body further comprises at least one light source and at least one photoelectric sensor arranged opposite one another on the periphery of the external window.