Alan Tudyk gave us a loveable droid character via motion capture with Rogue One's K-2SO, and Solo will be giving us L3-37 played by Phoebe Waller-Bridge. Though K-2 was brought to life soley by Tudyk wearing a mo-cap suit, Solo costume designed Glyn Dillon reveals that L3 is actually partly practical.
Here's his post on Instagram:
Until I see an actual BTS photo of Waller-Bridge, I'm going to assume that his explanation was that the actress wore most of the main bits of the droid, like the head, torso, and arms, and VFX simply replaced all of her limbs with wires and ‘guts'.
With L3 nowhere to be seen in Empire Strikes Back, some are guessing that she goes the way of K-2 and dies in the film. Besides that, some think that she'll be the A.I. running Lando's cyborg assistant Lobot. Either way, I'm sure a branch of the fandom is happy to see more droids being introduced in the films.
Though we don't have enough of L3 in the trailers to make a solid judgement of the character, it looks like she'll be a lot more irritable and rash as compared to K-2SO. Unlike K-2 who is meant to be an Imperial droid, L3 is actually said to be a mishmash of parts from different droids.
Catch L3 in Solo: A Star Wars Story when it comes out May 25.