LWB means "Long Wheel Base"
If you look at a pic of a LWB sammy compared to a regular sammy, the LWB is a lot longer. (Hence the name)
Yes, the red Sammy is a real picture. It's Jake Palmberg's rig. He's running Unimog axels and 44� tires. It's huge! I think there’s a few videos of his truck in the Vid section on the homepage.