I believe she can actually light his cigarette, probably a function of the same lasers or whatever that project her being focused to cause heat (perhaps this would not work with the portable emanator). Is it implied when she lays her hand against his cheek that K can feel this? Perhaps a sensation of warmth?
This ghostly sort of effect where an otherwise intangible hologram manages to interact with the "real world" would seem to be something the designers would want to offer.
Yes, the DiJi does have a slight effect on its surroundings. It's not heat, but rather a sense of static electricity when it intersects with real objects.
vfxblog: Just finally on that sequence, did I notice, right at the beginning when they merge, that Mackenzie’s hair gets a little bit affected by Joi?
Paul Lambert: Yeah, totally. Basically, we were showing Denis the sequence, and he wanted something a little bit more for when Joi first enters Mariette. The idea was that, because she’s this analogue electrically-charged kind of, I don’t know what you call it, something which is messing with photons kind of thing. He wanted Mariette to feel a little bit of a physical interaction from it, so basically, we rendered some strand of hair, which rose as she touched her, just for a bit of static.
The script refers to her as a "static wisp" with some presence, but evidently no heat or true substance. Note also that she uses a focused form of static electricity to light his cigarette.
Joi “takes” his hand. Static heightened by the conductive water clinging to his skin. She leads his hand to her waist. As if to dance.
She leans in close to his neck. Her exhaled “breath” tickles his lips. A smoky wet dream. He kisses her. She looks deep in his eyes. K kisses her neck, slowly... not breaking the illusion... The moment intensifies-- her breath escaping --
