Petronella is an American Country Dance originally devised by Nathaniel Gow in 1820 it came over to the US by 1890 and has mutated since. This is one variant, interpreted by Smukler and Millstone in 2008. It is a proper duple minor.
The earliest version is very similar to the dance described in the RSCDS book (the petronella turn is simplified and setting is replaced by balancing). It is a chance for the 1s to show-case their balancing skills — there are four balances and often the 1s tried to make each one different. As time went on the 2s got more involved in the dance, and eventually the balance and the turn switched orders into the form that is more common now-a-days.
See the Scottish version for even more examples.
The animation plays at 120 counts per minute normally, but the first time through the set the dance is slowed down so people can learn the moves more readily. Men are drawn as rectangles, women as ellipses. Each couple is drawn in its own color, however the border of each dancer indicates what role they currently play so the border color may change each time through the minor set.