Because of the faint trail which, at the top, ends in a change in brightness and direction, I wondered whether this was an asteroid burning up. I should add that the vector was consistent with the asteroid field (the Geminids) from the previous nights - and the wrong direction for the usual commercial aircraft flights.
My friend +Matthew Fowler, who is a superb astronomy photographer, while seeing my description but without seeing this image, has given some good advice about streaks -
"...meteors usually achieve their peak brightness just before the end of the streak so its probably a satellite. The bright flash is the sun catching the solar panels at just the right angle to reflect down to your part of the world. The change in direction could be lens derived especially if in the corner of the frame. These artifacts are a necessary evil when shooting wide open and tend to stretch and distort the tiny light source."