We claim the ornamental design for an electronic display device, as shown and described.
FIG. 1 is an orthographic view of the electronic display device according to our new design, which has eight cubelets as shown, each cubelet having three orthogonal partially-reflective and transparent exterior surfaces, with three orthogonal display screens, each display screen being situated beneath a respective one of the exterior surfaces;
FIG. 2 is a top plan view thereof, with the left-side, right-side, front-elevational, rear-elevational, and bottom views thereof being identical; and,
FIG. 3 is an orthographic magnified view as designated in FIG. 1 showing the display screens situated beneath respective exterior surfaces.
The broken lines in FIGS. 1 and 3 depict bounds of the magnified portion of the electronic display device and form no part of the claimed design.