I suspect they were closing in to make a better grouping for the camera. Strumming/picking slightly forward of the sound-hole on some guitars gives a more mellow, warmer sound, the tone hardens as you play nearer the bridge, but strumming right up the neck would have more to do with how the instrument was held than anything else.(Unless those cowboys were into "tapping", Van-Halen style)
Mmmm, maybe not.