I'm using my IPhone & don't know how to post links w/ it but click on the article referenced in the original article there are more pix and it's Pippa. Not sure she was w/ Eugenie, the second article mentions Pippa was w/ her bf and Eugenie w/ her mom. Not saying they weren't together just saying that they could have just happened to go to the same club on the same night.
Edited to add: Pippa was not w/ her bf (per another article) but a group of friends. BTW the same article reports all the fashion lines are coming out w/ similar pants - guess we'll all be wearing them soon