Some do :)
A vertical contrail. Planes fly straight upwards, right?
“A vertical contrail. Planes fly straight upwards, right?”
Especially commercial airliners. It makes the take off more exciting for the passengers.
Some do :)
Maverick and Goose, yes.
USAir FLight 808, not so much.
Any high altitude aircraft, coming from offshore (say Hawaii) and heading straight for you (say in LA), always APPEARS to be heading STRAIGHT UP.
IF you could follow the contrails (i.e. they did not dissipate in the wind), you would find they led to the horizon of the ocean.
For the same reason, the TOP OF MASTS on boats appears first, then the actual boat itself.
I live in the MIDWEST and I saw contrails in the sky that looked almost completely identical to the ‘mystery’ one in LA. There are some very high speed, high altitude winds that have been just wreaking havoc with clouds and arrow straight contrails this past week.
This whole thing is a nice distraction, but I assure you, that is all it is.
OMG!!!!! IT'S STRAIGHT UP!!!!! 
It's a 3-D effect projected onto a 2-D medium, with nothing to provide a sense of perspective or depth.
It looks sorta like a missile, but you have no actual data to support it, other than that.
But you shouldn't be worried about that. Here's a far more alarming picture of a couple of ships being driven straight down!
“A vertical contrail. Planes fly straight upwards, right?”
The image is only vertical from the angle at which the picture is taken. Hold a ruler on the angle of a plane taking off. The perpendicular view looks like a plane taking off, the horizontal view is shortened and goes straight up and down.
Especially if it's an incoming flight from Hawaii. /s/
Not necessarily.
Just curious, how far away do you suspect that contrail is from the individual taking the picture?