Not an overzealous FA. Laptops are not to be stowed in seat pockets for takeoff or landing. Some FAs are more vigilant than others in enforcement of this, however. A laptop stowed in a seat pocket isn't always visible to us as we complete cabin safety checks, so it probably goes unnoticed as often as not.

I remember reading of a case in BC a few months back where a woman was killed while driving when she hit a lamp pole or something while moving at 80km/hr. She was killed by a laptop that she had left on her back seat. The thing, I guess, went flying and whapped her on the back of the head when she came to an abrupt stop. If you consider that an aircraft moves at much higher speed than 80km/hr she while it heads down the runway during takeoff and landing, the regulation makes perfect sense. I don't enjoy bothering people to stow their laptops properly, but I do it. I'm responsible for the safety of the passengers on my flights, and should something untoward happen during our takeoff roll or landing, I'd would hate for someone who would otherwise have survived it unscathed to sustain severe injury just because a laptop hadn't been stowed correctly. I get your point about the 10lb textbook, but CARs are
CARs and we are required to enforce them.

I'm not sure offhand about the iPad. Possibly the FA who wanted it stowed had gotten a little carried away. Nonetheless, I'm sure that he/she was thinking of safety.