Yeah, these things are a tricky thermodynamics problem. The interior will be filled with steam, which is a gas, not a liquid, and so in that sense it will be dry. But even though it’s dry it won’t absorb water like air will. So it’s dry but nonabsorbent, which means it won’t make things soggy yet will leave foods’ natural moisture intact.
Or something like that!
It would be interesting to hear the designers explain the science and what exactly its special benefits are.
They have an exhaustive website but I haven’t had time yet to delve very deeply:
http://instantpot.com/technology/what-is-electric-pressure-cooker/