The ornamental design for a seatingball, as shown and described.
FIG. 1 is a front, left perspective view of the seating ball showing our new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines in the drawings illustrate portions of the seating ball that form no part of the claimed design.
The thin solid lines in the views have been provided for the purpose of illustrating the uniformity of the planar surfaces and the contour of the curved surfaces and are not a claimed surface pattern.