You're saying those photos are real? Don't 'insult my intelligence'. [=don't treat me as though I am stupid; don't expect me to believe those photos are real]
Most people were forced to work longer hours each week, and to 'add insult to injury', the company decided not to give pay raises.
They're understandably 'insulted' when no one asks for their opinion on a matter that affects them so much.
(..) Shh, shh, shh. They're right here. MURRAY: I don't have a personal problem with him, okay? SWEENEY: Don't insult my intelligence, Murray. You hate this child and I think I know why. I went out with his mother a few times. That was three years ago. It was nothing. Nothing. Really? Hmm. (..)1998 American History X