FIG. 1 is a front perspective view of a button cover in accordance with a first embodiment of my design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a cross-sectional view thereof, through the 6-6 line shown in FIG. 3;
FIG. 7 is a right side view thereof;
FIG. 8 is a left side view thereof;
FIG. 9 is a rear perspective view thereof;
FIG. 10 is a front perspective view of a button cover in accordance with a second embodiment of my design;
FIG. 11 is a front elevation view thereof;
FIG. 12 is a rear elevation view thereof;
FIG. 13 is a top plan view thereof;
FIG. 14 is a bottom plan view thereof;
FIG. 15 is a cross-sectional view thereof, through the 15-15 line shown in FIG. 12;
FIG. 16 is a right side view thereof;
FIG. 17 is a left side view thereof; and,
FIG. 18 is a rear perspective view thereof.
The dashed lines shown in FIGS. 1-3, 6, 9-12, 15, and 18 represent environmental structure and form no part of the claimed design. The dotted lines shown in FIGS. 6 and 15 represent the borders between claimed subject matter and unclaimed subject matter and form no part of the claimed design.