What does "dog on the sofa moment" mean?
Her dog clearly really enjoys being on the sofa (like most dogs), even if he doesn’t have any right to be there. I don’t think it’s a common idiom, but the meaning seems clear to me. She’s comparing her emotions to her dog's, using both anthropomorphism and metaphor. It gives a sense of her enjoyment at interviewing this person along with her mild "imposter syndrome".