In one general aspect, the subject matter described in this specification can be embodied in a display case door that includes an insulated panel assembly that is transparent to visible light. The door further includes a door frame extending about and secured to a peripheral edge of the insulated panel assembly, an electronic display overlaying the insulated panel assembly, and at least one display retainer secured to the door frame and having a coupling end that mates with the electronic display to releasably secure the display to the door frame.