I prefer holding the Biceps but holding the Gi works too, specially if you cannot reach your biceps. I use this position a lot and I mostly train with GI.
About the size of the pictures, have you tried to watch the slideshow on fullscreen? You need to click on the slideshare icon and visit their site. Although it loses resolution, you can see a lot bigger then.
Anyways, I used pictures taken from a seminar last year and will do 2 or 3 more in the same way just to get used to it, but I intend to shoot pictures specially for slideshows and this will improve the quality, maybe posting one picture per slide and the explanation on the following slide, I will keep on trying.
Nothing beats a teacher at class. Videos, pictures and slideshows can help but the most effective way to learn is to have someone showing you the position and drilling it many times, then trying to do when sparring.
Today I was training with one of my students in Italy and used this submission once again. I hold my biceps
Posdrawiam
Na razie