From a pose in a common meme
I can only assume this is some dystopian cyberpunk story where the cupcakes turn out to be a lie.
Just look up "Oh Look! Cupcakes" on google images and you'll get it.
I still don't get what they're doing.
It's just a pose from that meme. It's pretty obvious in the original what they're doing. I'm told it's quite too clear what they're doing in my version as well, the waitress in the pub where I drew it seemed mildly offended.
In the drawing it looks like suppository insertion (my first thought) or fingering. I would guess the same in the original except that it looks like the hand of the woman on the left is too low to be touching any of the parts, and the woman on the right is wearing underwear anyway.
.... *was expecting actual cup cakes*
*o* very nice