There may also be some symbolism in the story which may be important. In his book How To Change Your Mind, Michael Pollan mentions breathing techniques and meditation as other ways of accessing this part of our brains. Wellington is said to be magic mushroom capital of New Zealand and would have been the perfect place for Bertha to experiment with psilocybin.
Which would mirror the paralysis that Bertha feels. The reader can clearly see this situation for what it is, yet Bertha cannot. This suggests that Bertha is gay but is unaware of this.
The story gives us a bird's eye view of the dinner party, which is attended by a couple, Mr. Just that. It is only after Bertha analyzes her feelings towards Pearl that she realizes that the connection she feels with Pearl is their mutual attraction for Harry, and coming out of her "blissful" reverie she makes the discovery that Harry and Pearl are having an affair.
As Bertha is a grown woman, she does not know how to express this feeling in a way deemed appropriate for an adult. The writing shows Bertha depicted as a happy soul, though quite naive about the world she lives in and those closest to her. Pearl is positively characterized by Bertha's thoughts and feelings towards her.
Bertha is interested in expressing these internal desires externally. When Harry compliments the food, Bertha again feels almost overwhelmed with tenderness and joy.
This suggests that Harry is a person who worries about how he presents himself to the world.