Different from Switcheroo, this card puts the other cards in the bottom of your deck.
With Switcheroo you can draw the same card. It is the same with Card Trader continuous spell, if you get unlucky you can draw the bad timing card again.
It says "when" instead of "during the turn this is normal summoned".
So I think it means opponent can't activate in response to it's normal summon e.g. flood gate. It's N card for a good reason.
