With stuff like this I always refer to how my mom uses computers. (Note - This a person who thought when you copied text on her iPhone that the text magically went into her finger, only to have to click paste with another finger so the text didn't get lost in her finger...)

I agree. There is no way she would know to scroll properly in this interface and in most cases would get confused and give up. The objective of the presentation is to make it easy for someone (like my mom) to understand A/B testing. Make it a video, or at least provide a link to a video version.

EDIT: This akin to Amazon's usability - http://www.nngroup.com/articles/amazon-no-e-commerce-role-mo... i.e. once some behavior is establish on your site, keep it that way, but doesn't mean you need to emulate it.