The ornamental design for an electronic flashdevice, as shown and described.
FIG. 1 is a front perspective view of an electronic flash device showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is an enlarged view showing the portion defined by lines 4-4 in FIG. 1;
FIG. 5 is an enlarged view showing the portion defined by lines 5-5 in FIG. 2; and,
FIG. 6 is an enlarged view showing the portion defined by lines 6-6 in FIG. 3.
The features shown in broken lines in the drawings depict environmental subject matter only and form no part of the claimed design. The dash-dotted lines denote the boundary of the claim and form no part of the claimed design.