An interesting concept.
School shootings and workplace violence probably led to the creation the concept of Bulletproof Whiteboards These can't be very cheap.
When I first read of the concept I was thinking of the roll-around type of whiteboard that is maybe 4X8 feet. That type of board could be wheeled in place at the entrance to the room as another level of protection in blocking entrance and keeping the shooter from shooting into the classroom.
As for the handheld type of board pictured--the clipboard is a little small! Perhaps better than nothing, but...