Spoiler me please, what is Oh Seonhye actually doing ╥﹏╥

You're gonna be dissapointed by me because I actually have no clue myself, but I'm GUESSING it's just her way of "speeding things up" and testing Yeryeon, perhaps setting her up to become the company's heir, by digging Seori so deep into the dirt she can't escape. Yeryeon will look that much better as an heir by virtue of solving the whole ordeal.
But that's just a theory, a game theory.

This is also what i'm thinking