Thanksgiving-appropriate philosophy as we partake in holiday meals:
A good time to think about how "he who, not thirsty himself, mixes mead for another, and he who, being thirsty, drinks the mead, are in just the same state of pleasure:"
While we are getting it filtered through a negative-sounding Cicero, sounds to me like this example was used to emphasize the viewpoint that the person who -- "thirsty himself" -- meaning not in pain, falls within the definition of pleasure just as much as the person who chases away the pain of thirst by drinking!
This variation does not stress the host and the guest being "totally without pain," but that might be implied too from the fact that no other aspect of their experience is mentioned.
So either way, from (1) the "whole person totally without pain" perspective (if we assume that) or (2) from the "discrete experience" perspective (that the experience of drinking while thirsty falls under the same label of "pleasure" as the person who is not thirsty at all) the point is being driven home that "absence of pain" can mean either stimulation or simply normal life without pain.