I was hoping it wasn’t carpet, but I think it’s durable textured carpet. https://gocarpetcleaningatlanta.com/about-textured-carpet/ There are better photos of the pool area in this article: https://www.realtor.com/news/unique-homes/erickson-home-midcentury-minnesota-steel-bridge/ This house intrigues me. I love it but also don’t. Also, per the article, the current owner has never filled the pool, so the agent says the condition and functionality of it are uncertain.