The ornamental design for a fashion accessory, as shown and described.
FIG. 1 is a perspective view of a fashion accessory, showing my new design;
FIG. 2 is a perspective view thereof;
FIG. 3 is a front elevational view of FIG. 2;
FIG. 4 is a rear elevational view of FIG. 2;
FIG. 5 is a left-side elevational view thereof;
FIG. 6 is a right-side elevational view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is an enlarged detail perspective view thereof, taken from the area 9 of FIG. 1.
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 stitching, and are part of the claimed design.