I claim the ornamental design for a wearable sign cube, as shown and described.
FIG. 1 is a perspective view of a wearable sign cube, showing my new design, illustrating a plurality of sign boards engaged with a frame of the invention;
FIG. 2 is a front elevational view thereof, the rear elevational view, left-side elevational view, the right side elevational view all being a mirror image thereof;
FIG. 3 is a top plan view thereof, illustrated with all four removable sign board engaged with the frame of the invention;
FIG. 4 is a bottom plan view of the frame thereof, illustrated without the removable sign boards engaged thereto; and,
FIG. 5 is a front elevational view of the frame thereof, illustrated without the removable sign boards engaged thereto, the rear elevational view, left side elevational view, and right side elevational view being a mirror image thereof.
The broken lines showing a person in FIG. 1 and a specific banner message in FIGS. 1-2 are included for the purpose of illustrating the wearable sign cube in use, and form no part of the claimed design.