Rosie O'Donnell has personally reached out to Jessica Simpson and asked her to guest star on 'The View' during her first day of work. There is some history between these two. Back when Jessica was a big ol' nobody, Rosie had her on her show and gave her some words of encouragement that Jess will never forget. I guess this is Jessica's way of saying thanks for the support.

Jessica Simpson will appear on the first episode of The View to star new cohost Rosie O'Donnell, on Sept. 5, PEOPLE has learned. "Rosie herself reached out to Jessica," says a source close to Simpson about the singer-actress's guest shot.
The two have a long history together, going back to The Rosie O'Donnell Show, which aired from 1996-2002, when O'Donnell was riding the crest as TV's highly rated "Queen of Nice."
"When Jessica was just starting out, none of the big shows were interested in her, but Rosie took a chance on her and Jessica never forgot it," says the source. (source)