The ornamental design for a decorativeornament for a bag, as shown and described.
FIG. 1 is a front perspective view of a decorative ornament for a bag;
FIG. 2 is a front view thereof;
FIG. 3 is an enlarged, fragmentary left side view thereof (the right side view is an identical or mirror image of the left side view);
FIG. 4 is an enlarged, fragmentary front view of the stitching included on the bottom left corner of the decorative ornament of the first embodiment;
FIG. 5 is a front perspective view of another embodiment of a decorative ornament for a bag;
FIG. 6 is a front view thereof; and,
FIG. 7 is an enlarged, fragmentary left side view thereof (the right side view is an identical or mirror image of the left side view).
The broken line showings of the decorative ornament for a bag in the figures are for the purpose of illustrating an environment only and form no part of the claimed design.