To come up with instant personalities for background flavour NPCs, just adopt various occupational stereotypes. Sally has already made good use of The Librarian, and here we see the GM adopting The Schoolteacher.
[Reminder: Our guest commentators have not seen Rogue One. Part of the fun is seeing how their untainted impressions re-interpret the movie through the lens of our comic.]
Really, a necklace with a mysterious crystal is obviously way more interesting than anything the Rebellion leaders could possibly be talking about.
I don't know what Bria could really find by examining it. Even if she discovers some markings, she will likely not know what they mean. I feel like Chirrut would be better at sensing energy or recognising the shape or something. Being a monk and inherently knowledgeable in cool, mystical stuff. And I don't know who else in the party has a hope of a good Lore check. Maybe Bodhi?
So Dr. Light, or at least someone who looks like Dr. Light, or at least the Dr. Light as seen in the 16-bit sprite section of Bob and George, is just droning on and on in his talk to the Rebel crowd, and we see Bria almost nodding off and falling asleep, only to realize there's something on her character sheet; clearly, the long winded and ongoing monologue of the NPC is just causing the players (not just the player characters, the actual players themselves) to lose attention, and have their focus wander, typically a bad sign for any sort of GM that is paying attention to the player's enjoyment of the game, and a good indication that the players need to be pro-active, protagonistic, and take action needed to advance the plot, as the NPCs, almost by definition, will not be advancing the plot, but are merely the background for the players to act against; letting players wait for the NPCs to come to a conclusion, or a committee decision can generally be regarded as a bad use of people's time, and uninteresting, or uneventful actions in the story that is taking place can consume far too much time, to the point that nothing actually happens of any substance, and WHAT DO YOU MEAN THERE'S A CHARACTER LIMI
General Dodonna: ... differences in semantics may seem irrelevant but in a significant proportion of projected statistics the consequences can have a critical impact on—
Bria: Hey, I just noticed a thing on my character sheet!
Bria: "A necklace with a mysterious crystal on it". That's mysterious.
Chirrut: I'm sure you've noticed that before.
Bria: Really? Anyway, I've just noticed it again. That's pretty mysterious. I examine it.
Nower Jebel: Excuse me, Miss Tharen, are you listening?
Bria: No. I'm just checking my inventory.
Nower Jebel: Well! I hope you've brought enough for all of us!