Portable display device

FIG. 1 is a bottom front perspective view of a portable display device showing our new design;

FIG. 2 is a bottom rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a left side view thereof;

FIG. 7 is a right side view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines shown illustrate portions of the portable display device that form no part of the claimed design.

The shade lines in the Figures show contour and not surface ornamentation.