Jessica Simpson said she was feeling “angry” and “defensive” in a response after her fans expressed concern about her appearance in a Pottery Barn advertisement. Over the weekend, the singer appeared in a video on Pottery Barn Kids’ Instagram page, walking viewers through her 3-year-old daughter’s room. Commenters jumped on Simpson’s physical appearance and vocal delivery in the video. “Something is wrong here,” one wrote. “Is she OK?” asked another. Simpson, 42, responded in a new video on Sunday singing along to her song “Party of One.” “I needed to be in my studio today because this is wher…