Girt Bar thank you for that image. As a pilot it tells me a lot about other pilots who are not doing their job properly.
The wing looks like a 737 series. Anybody know what type the aircraft involved was?
Boeing have done a lot of studies recently sticking expanded polystyrene blocks onto the upper surface of a wing to simulate snow build up. They had observed that certain operators of Boeing aircraft around the world have survived for years after taking off with snow on the upper surfaces of the wing, which we thought, as pilots anyway, would lead to disaster.
I understand that it is type specific. For instance the 737 is more critical, and can have big problems with even light snow on the upper surface of the wing, especially if it is not symmetrical whereas the 747 series is less prone to lift loss with such contamination.
From my point of view, I would really have appreciated one of the cabin crew telling me about that wing in the photo. I would have got de-iced.