If you really want to ride the monorail, you can exit the monorail at the Convention Center, and then board the Downtown Strip Express bus southbound, which will drop you at Wynn/Fashion Show.
The monorail was intented to connect the hotels, the airport, and the convention center (prior to Wynn/Venetian). Fashion Show wasn't considered.
The City Center tram and the tram between Mirage and Treasure Island are nearly as interesting, and both are free. You could cross over to Bellagio and take the City Center tram to the shops at City Center, although that's a very roundabout method.