I have no particular knowledge of the mechanics of putting the show together, but it appears as though each expert is individually brought in, sat in a Comfy Chair, they record a bunch of science/snark, and eventually it's all edited together into a series of episodes.
Something about having people sit in Comfy Chairs brings out differences in posture. (Somehow I've gotten sensitized to this and notice it.) The men mostly-in varying degrees-sit back and sprawl out, seemingly trying to fill as much space as possible, in time-honored gender-stereotype manner. The women perch at the front, legs crossed tightly, leaning forward just a bit, filling much less space. One of the men is more tightly curled than the others, though. Carin Bondar tends to sit with her legs up on the cushion, cross-legged or sitting on one. In that respect Carin and I are very much alike. (Otherwise, we're not so alike. She's a biologist studying entire animals. As a chemist I stick to molecules.) (On the third hand, like Carin, I like talking about penises. So if you see someone curled up on top of a chair talking about penises, it could be either of us. If you saw it on the Science Channel, however, it was her.)