The ornamental design for a footpillow, as shown and described.
FIG. 1 is a front perspective view of a foot pillow, showing my new design in a used configuration by a person;
FIG. 2 is a rear perspective view thereof in a natural configuration;
FIG. 3 is a right-side elevational view of FIG. 2;
FIG. 4 is a left-side elevational view of FIG. 2;
FIG. 5 is a front elevational view of FIG. 2;
FIG. 6 is a rear elevational view of FIG. 2; and,
FIG. 7 is a top plan view of FIG. 2, the bottom plan view being a mirror image thereof.
The broken lines showing a person in FIG. 1 depict environmental matter and form no part of the claimed design. The remaining broken lines represent portions of the foot pillow that form no part of the claimed design.