[tb]

It's an art piece, not a serious piece of espionage equipment, hence its form reflects its (symbolic) function.

[iamdave]

I don't think armed guards see the silhouette of a grenade, a device that can maim, wound, injure or worse kill a number of people in the terms of "espionage".

[indiecore]

I think you've missed the point

[pippy]

If any security personal saw a transparent plastic flashing light shaped like a grenade they'd likely write it off as a trinket.