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.
(..) ...Cedric Diggory was murdered... ...by Lord Voldemort! The Ministry of Magic does not wish me to tell you this. But not to do so, I think, would be an insult to his memory. Now, the pain... ...we all feel at this dreadful loss reminds me... ...and reminds us... (..)2005 Harry Potter and the Goblet of Fire