Yes, the Canon EF 35 IS is f/2.0 and 1 stop faster than the Sony and yes, the EF 40/2.8 pancake is tiny and brilliant (I have it). And since we use our lenses mounted on camera I think it is a good idea to show lenses mounted on functionally comparable cameras for size comparisons.
Also, as I repeatedly stated, Sony is a bad example in terms of "more compact lenses" due to their poor choice of FF lens mount. But even despite of this I presented a few noteworthy examples of very compact lenses. So pointing to size of Sony FE lenses has little relevance with regards to "will a new Canon EF-X mount allow for more compact lenses"? We don't know, until we at least know basic mount parameters and get an idea what design goals Canon is pursueing. However, with properly chosen lens mount parameters it will be possible to [also, but not only] design lenses in the most frequently used focal length range that are more compact than corresponding EF lenses. Exemptions possible, I don't think you can make an FF 40/2.8 much smaller than the EF.