The ornamental design for a balloonilluminatingdevice, as shown and described.
FIG. 1 is a side perspective view of a balloon illuminating device;
FIG. 2 is a front view of the balloon illuminating device;
FIG. 3 is a back view of the balloon illuminating device;
FIG. 4 is a left view of the balloon illuminating device;
FIG. 5 is a right view of the balloon illuminating device;
FIG. 6 is a top view of the balloon illuminating device; and,
FIG. 7 is a bottom view of the balloon illuminating device.
The broken lines defining a container and adaptor below the claimed cap depict environmental subject matter that forms no part of the claimed design. All other broken lines show portions of the article not claimed. The broken lines form no part of the claimed design.