Jayce and viktor just ended a very tense conversation with another boss(silco) who was going out of line and getting on viktor's nerves.
But it was a chance for Powder to make a name for herself, a chance to rise above the other young, desperate academics of Piltover. Yes, Lux also lived in Demacia and sure, things had ended, well, “awkwardly” was probably the kindest way to put it. Powder thought it was the perfect opportunity: an offer from Jayce and Viktor to assist them in establishing the Hexgate trade lane to Demacia.