It is difficult to tell if that is icing, but the general rule is that the wing upper surface should be clear of all contamination. When the wings were checked, perhaps they were clear, and maybe the ice formed later. However, the Captain is supposed to check before take-off that the aircraft is still clear of contamination. The engineers often check the wings in the first place and order de-icing if required, and/or an agency is employed to predict icing conditions. In theory, the cabin crew will tell the flight deck if there are any changes or concerns before take-off, and in the airlines I have flown for, this would be taken seriously by the flight deck.
The OP could have stood up and banged on the cockpit door and refused to sit down until the aircraft had been de-iced, but that would take big b*lls.
Can a passenger send an ASR to the company or CAA?