This is an old presentation trick, but it’s good.
It was started by an advertising agency that would produce carefully worked-out presentation concepts, but always include a blue duck somewhere in the visual. When it came to the feedback, clients would say: “We love it, apart from just one thing — can you take the duck out?”
The creatives would sign a little, make a brief but lacklustre defence of their ultramarine mascot, then agree to the change — knowing everything else was going through. And they used this trick for years.
It’s a simple bit of psychology, really, reflecting the human desire to meddle ever so slightly. The clients would feel they had made a crucial intervention, little knowing that they had been deceived into approving everything else.