KM,

From your pictures it looks like your grip on the razor needs to be adjusted. I think it's your grip which is causing more pressure to be applied to the spine of the razor, lifting the blade slightly off of your strop. A better hand position would be one in which the ball of your thumb rests completely flat against the shank and your index knuckle should be pointing back at you while keeping your wrist straight. This will allow your natural wrist tension to keep the blade in contact with the strop.

Cheers!