Since no one else has addressed this directly, it’s worth pointing out that in this context the assumptions made are not, in fact, reasonable biochemical assumptions. The person who came up with this figure effectively assumed that something as complex as the simplest currently-existing life forms would have spontaneously arisen, instantly, through shear chance variation of molecular arrangement in a thermal mixture. This is an extreme straw-man. I doubt anyone with significant knowledge of molecular biology seriously believes that life-forms as complex as any we recognize today are likely to have originated in such a fashion.