No, it is not flipped through the compression stroke, that would result in the engine starting and running backwards. The idea is to get it just far enough into the compression stroke for ignition to occur. The bump from the firing reverses the engine and the engine keeps running forward. I grab the spinner or prop hub and spin it backwards into the compression stroke. My fingers release the hub before the compression stroke even begins, it's the momentum on the prop that finishes the job.

If you have a four stroke engine handy, try this. Close the throttle completely (engine cutoff, not idle) and turn the prop. WHERE DID THE COMPRESSION STROKE GO!!! Well the compression stroke dissapeared because the closed throttle didn't let any air into the cylinder for the piston to compress. When the intake valve closed, the cylinder had a vacuum in it that sucked the piston up the bore during the compression stroke.
When you back flip the engine with the throttle closed to idle, you initially have a cylinder full of air/fuel mix that ignites almost as soon as the compression stroke begins. This reverses the engine and the intake stroke goes by so fast that the cylinder can not fill with much air. Because of this, there almost is no compression during the next compression stroke and the mixture does not ignite untill the piston is nearly at the top of the stroke.

Once you learn this method, you will throw your electric starter away and your spinners won't be marred by starter cone burns.