The ornamental design for a shower organizer, as shown, and described.
FIG. 1 is a top perspective view of a shower organizer showing our new design;
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a right side elevation view thereof (with the left a mirror image thereof);
FIG. 6 is a top plan view thereof; and,
FIG. 7 is bottom plan view thereof.
The broken lines show portions of the design that form no part of the claimed design. The shower organizer is shown with symbolic breaks in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.