We sometimes describe this as “hookers and sliders”. On beats 1-4, the dancers in positions 1 and 4 (“sliders”) move straight along the sides of the set, #1 heading for position #3, and #4 heading for position #2. The dancers in positions 2 and 3 (“hookers”) hook around each other (and also around #5), with #2 ending up in position #1 and #3 ending up in position #4. On beats 5-8, the same thing happens. Note that the dancers who were “sliders” on beats 1-4 are now “hookers”, and the dancers who were “hookers” on beats 1-4 are now “sliders”.
The same happens on beats 9-16, at which point the dancers are back in their original positions.