>>153261
For me it's in the juice itself, and the implied hucow/exploitation angle that comes from it. Get inflated with water, you're a water balloon. Get inflated with air, you're a blimp. Get inflated with juice? Now you're factory property. The process is going to long and arduous, requiring expensive equipment... it makes sense that your inflator doesn't just have the right to seek reimbursement for that, but maybe even pursue gross profit... The inflatee wasn't just a brat who wound up as a sphere, now they get to be exploited, too! The inflator gets to make thousands if not millions off of the juice they squeeze out of the berry while they just sit there and chew and chew, all day long.
Even if the juice isn't necessarily harvested for profit, there's the fact that 'juicing' is usually implied to involve a lot of squeezing and stimulation of various erogenous zones, adding a nice bit of 'sexual agency' play to the mix. I know that people complain about it being unrealistic/autistic when a character screams 'juice me!' But I like it, because the inflatee isn't really asking to be defiled/fucked for their own pleasure, but for their own good. Sex isn't a desire, but a necessity for their own survival, one that the inflatee is privileged to offer or deny at their discretion. I feel like people who like air/water tend to be more into popping precicely because those two methods often don't involve an agreed upon form of 'deflation' like blueberry does.
In addition, I like how blueberry is such an easy 'hands free' type of inflation. It doesn't require air hoses or fire hydrants, just a piece of funny gum, or some other sort of catalyst, that binds the victim to immobility basically from the inside-out.
As for the people who like loompas, or wonka songs, or any other signifiers from the scene. Yeah, you could cry autism, but more generally I think its just that, this scene hits peoples brains like an atom bomb, it makes sense they would hang onto little details like that. Most people who dislike wonka signifiers tend to be people who got into blueberry later in life, through other fetishes.