The ornamental design for a carriage accessory, substantially as shown in the attached drawings.
FIG. 1 is a perspective view of the carriage accessory design with lighting;
FIG. 2 is a top view of the design corresponding to FIG. 1;
FIG. 3 is a bottom view of the design corresponding to FIG. 1;
FIG. 4 is a right-side view of the design corresponding to FIG. 1;
FIG. 5 is a left-side view of the design corresponding to FIG. 1;
FIG. 6 is a front view of the design corresponding to FIG. 1;
FIG. 7 is a back view of the design corresponding to FIG. 1;
FIG. 8 is a perspective view of the carriage accessory design as it may be used with a wheelchair carriage, where in the wheelchair is shown in dashed lines to indicate environment but does not form a part of the design; and,
FIG. 9 is a perspective view of the carriage accessory design as it may be used with a stroller carriage, where in the wheelchair is shown in dashed lines to indicate environment but does not form a part of the design.
Wherein the shaft portions are shown “broken” to indicate that the shaft portions may be any suitable length, and the crown is shown in dashed lines to indicate environment but does not form a part of the design.