There's not a lot to say about this one, for it exists largely as a transitory episode, comprised of the time-honoured superhero tradition of bringing a single confidant in on the secret, and in finally bringing Arrow and the Flash up to speed on Mari's existence.
They actually turn up on her doorstep looking like this.
Mari choses her foster-father as her confidant, who all things considered takes it pretty well. She treats him to a demonstration (which doubles as a quasi-test to herself) of what she's capable of, channelling the strength of an elephant and the agility of a spider, but stopping short of an eagle's flight at the brink of a high rooftop.
As ever, the best part is the visual representation of the necklace's powers at work.
But to her at least, the most pertinent thing concerning her necklace is the off-chance it could lead her to some answers about who she really is.
Which is also the question being asked in Star Labs. This is our first look at animated Cisco, who tells Barry that a "facial recognition algorithm" that Felicity installed has identified Mari as a meta-human. Of course, we know she's not exactly. It's the necklace that's giving her these superpowers, in keeping with the underlying thematic milieu of Vixen being based on magic, just as Arrow's is crime and The Flash's is science.
It's at this point that the codename "Vixen" is spoken for the first time. Unfortunately, it's coined by Cisco on the basis of how hot he thinks she is. Urgh. I really hope Mari gets the chance to embrace this name on her own terms, and not just benignly accept it.
And with Arrow and the Flash arriving on Mari's doorstep and giving chase when she bolts, we're more or less caught up with the opening sequence of the very first episode. Of course, it's unclear why a) they turned up in full superhero regalia, or b) why she responds by fleeing into the night, but hopefully they'll get cracking on the plot from here on out.
After all, there's only three more episodes to go!