The bottom line is operating income, not revenue. And WSM had an operating income of ~$1.5 billion last year.
The FTC found seven products were falsely advertised, starting with a mattress cover. But Pottery Barn sells over 10,000 products, in fact there are over 500 products in their bedding section alone. And Pottery Barn is just one part of WSM.
It’s near certain that a $3 million fine wiped out whatever profit these seven products made for WSM, and then cut into profits made by other products. So breaking the law was not a profitable strategy for WSM.