I'm not sure, pulling might be easier than pushing? I guess the difference is you are stretching in the air and coming back to your resting state while pushed

I'm not sure, pulling might be easier than pushing? I guess the difference is you are stretching in the air and coming back to your resting state while pushed against the glass rather than the opposite. Also you might be working around the fact that your thumb covers the content more when using the right hand. What I've found myself doing is using two hands.