It hasn't been cut and re-welded, the frames are just different sizes in the two photos.
If you look at the geometry for this model the head tube lengths of different sized frames can vary from 100mm to 155mm.
The bike in the ad is listed as having a large frame, this is probably the 20.5" frame which has a 155mm head tube.
The bike photo on the Rocky Mountain website looks like it's probably a bike with a medium or 18" frame which has a 110mm head tube.
The silver sticker as previously mentioned is probably from the bike shop that originally sold the bike.