Excuse me!? I have to pay YOU extra to keep MY comission PRIVATE!? If a customer doesn't want you to show off the work they paid for you don't nickel and dime them for More money, you say, "Okay I understand. Thank you for letting me know."
This is your point of view that differs drom my. I like to share my complete work on social media. If the customer does not want this to happen that that requires extra fee. Thank you for understanding.