This picture taken by someone who says they were an off-duty flight attendant is causing considerable consternation in UK regulatory circles. And it's being energetically discussed on Pprune.
It was sent to the UK's greatly respected CHIRP operation which is a confidential safety reporting system in which incidents are disidentified.
The F/A says (s)he told the senior F/A about the snow before take-off but the aircraft departed anyway. This picture was taken during the ensuing flight.
I'm not sure what type it is - no obvious sign of a nacelle, but maybe it's out of frame. If it's a hard-wing type though then this is really not a great situation.
In the Flight office we several times discussed what we would do if we found ourselves on an aircraft which appeared to be about to take-off with something amiss. I mean even if you knew you were right, what do you do exactly to stop the take-off going ahead? Imagine you're just about to roll on an MD-80 with no slats/flaps deployed.