Its pumpkin juice in the canisters. Kat has that slutty Professor McGonagall look going on that only the pinnacle of gilf succubuses knows how to flaunt.Improbable that it is the Super-Viagra. Sophia´s invention is potent even in small doses (at least the newest version), as we learned during the game.
What Edwin and Warren hold looks like gas canisters. so what kind of gas? Laughing Gas, Helium? Or something more sinister and freaky, since Kath is seemingly losing it more and more, like Halon or Blaukreuz (Blue Cross), to see how long they can stand it. For those not knowing it, Blaukreuz is the German groupname for chemical agents like Adamsit and Clark I-III. German artillery shells filled with it were marked with blue crosses, since Germany colourcoded her chemical weapons. Trivia fun fact: Weißkreuz is the groupname of a different type of chemical warfare agents, as for the famous anime series I truly doubt the creators do not know what Weißkreuz means, since they could have used "weißes Kreuz" which has other meanings.
Still I am not sure Kath would go so far to use dangerous gases in the Competition, but then again she destroyed Felicia´s life with glee and gloating. I would not put it past her to use dangerous stuff.
You have the super athletic Ginny Weasley and epilogue Hermione Granger doing one last test in the background. The hints are all there.