Touch the glass the grandkids tell her. So she dutifully touches it before getting the shock of her life as a shark smacks against it, cracking the pane and sending her hurtling to the floor.
The "attack" took place at the International Spy Museum in Washington, D.C.—and the tank in question isn't really a tank, but a virtual one aimed at scaring the crap out of unsuspecting grandmas.
Looks like it worked. As one YouTube commenter put it, "That's Jawesome."