FIG. 1 is a perspective view of an ornamental design for a lotion pump head;
FIG. 2 is a front elevation view of the lotion pump head of FIG. 1;
FIG. 3 is a rear elevation view of the lotion pump head of FIG. 1;
FIG. 4 is a right side elevation view of the lotion pump head of FIG. 1, the left side elevation view being a mirror image thereof; and,
FIG. 5 is a top plan view of the lotion pump head of FIG. 1.