The return of an old enemy is always a dramatic moment. You don't need to establish how awful or badass this character is - the heroes already know. And this is why villains should get away sometimes. If the heroes fail to deal with someone bad, it's only a loss from their point of view. For the GM, it's solid gold.
Commentary by memnarch (who has not seen the movie)
BB-8's definitely not been spotted! Phasma would have commented on that capture otherwise, I think. Still, not a great time to try and save the humans given the location, but Solid Snaking it behind them until an opportunity presents itself could work quite well for BB.
I haven't looked up what it's from, but I'm pretty darn sure Phasma isn't quoting poetry in that last line. That sounds more like a movie tagline or song lyric. I feel a bit like Pete; if Phasma wasn't quoting poetry, they were ranting about the First Order. A line like this feels abnormal. Maybe in line with Grievous though?
Also? I think I'd have to say the chrome armor is also not great inside a ship like this. I keep thinking those lights or tubes reflecting off the dome are paint splotches. Not a great look for a senior officer type.
Transcript
GM: You hear the tramp of booted feet behind you.
[SFX]: clomp clomp
Finn: We turn around.
General Phasma: Rejoice! henceforth I am omnipotent. All else had been subdued to me.
Finn: General Phasma.
General Phasma: Finn. The wolf returns to the fold.
Rose: What does she mean?
General Phasma: He didn’t tell you? The past is never dead. It’s not even past. He’s a spy working for me.
Finn: We covered this last time! The blaster in your face was a hint!
Finn: I pretended to be a spy to find Gil’s killer. I work for the Resistance now!
General Phasma: There’s a gentleman that’s going round, Turning the joint upside down. Stool pigeon!
Rose: If he defected to the Resistance, that makes him an ohming pigeon.