Fragrance diffuser bulb

FIG. 1 is a perspective view of our new and ornamental design for a fragrance diffuser bulb;

FIG. 2 is a front elevation view thereof, wherein the rear elevation view is identical to the front elevation view;

FIG. 3 is a side elevation view thereof, wherein the fragrance diffuser bulb has been rotated to the right by 45 degrees with respect to the front elevation view;

FIG. 4 is a left side elevation view thereof, wherein the right side elevation view is identical to the left side elevation view;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a front elevation view thereof, showing the fragrance diffuser bulb use with an electrical fragrance diffuser.

The broken lines in the figures are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.