We claim the ornamental design for a seating element, as shown and described.
FIG. 1 is front view of a seating element;
FIG. 2 is rear view of the seating element;
FIG. 3 is a side view of the seating element;
FIG. 4 is a top view of the seating element;
FIG. 5 is a bottom view of the seating element; and,
FIG. 6 is a perspective view of the seating element.
Applicant notes that the side view of the seating element, as shown in FIG. 3 is representative of both a right side view and left side view of the seating element. Any subject matter shown in dashed lines, and any surfaces of the design not shown, including interior surfaces, form no part of the claimed invention.