On /pol/, you're not really sure if they're actually racist or not.
On /fit/, you're not really sure if they're actually gay or not.
On /a/, you're not really sure if they're actually that pathetic or not.
On /v/, you're not really sure if they actually like games or not.
On /r9k/, home of the robots to which you refer, you're not really sure if they're actually that autistic or not.
I'm sure there are plenty of robots who actually are on the spectrum. On /r9k/, as is the case with the rest of 4chan, it doesn't actually matter. Autism is the canvas on which they paint. In this case, they paint with shit that's been fermenting in a jug in the corner of their room for the last six months.
Actually, the word 'ferment' is pretty apt in describing how /r9k/'s..."culture" has evolved. The board was created to be a second attempt at /b/, which had by that point devolved into constant shitposting. It was designed with an automated mod (the robot for which the board is named) that prevented reposting content. For some reason or likely reasons, people started using it as a venue to bitch about their shitty lives; loneliness and lack of a gf were popular topics. Thus did the board evolve a certain personality based on the gradual exaggeration of the stereotypical poster.
Recently, the mod was removed as moot finally gave the fuck up on what was once a pet project of his. This, to continue the metaphor, was essentially like an uncorking. But remember that this isn't some scotch whiskey or whatever. It's shit. In a jug. And it smells a lot like self-parody, as well as shit. The end result of these years of fermentation is a character represented by a sort of unholy trinity: Wojak the feels guy, Pepe the sad frog, and Smug Pepe the...the Smug Pepe. 90% of all reaction images posted on /r9k/ will involve one of these three in some way. Sometimes two, sometimes all three. They refer to outsiders/those without autism as "normies," they refer to the boyfriends of girls they lust after as "chads," and say "REEEEEEE" a lot. That last one is them mimicking a rainman-esque autistic outburst as well as a screaming frog. As you can guess, they're a weird kind of xenophobic.
To finally answer your question, the "robot," as he has become defined, is a ~22-35 year-old manchild with autism so severe he has become emotionally indistinguishable from a six year-old. He lives with his mom (his father has abandoned both of them in disgust), subsides on kids' menu food (chicken tenders, referred to as 'tendies' is the most memetic robot cuisine, but I've also seen stuff like mac and cheese, mozzarella sticks, etc), has no job but uses a currency called 'GBP' (good boy points) that his mother awards him for every action he takes that doesn't drive her closer to suicide, regularly makes public displays that involve screaming and shitting himself to punish his mother for not buying him whatever video game/candy bar/bag of tendies has caught his eye, and wishes he had a gf. He and his fellow robots will converse with one another about any of the above topics.
TL;DR NORMIES GET THE FUCK OUT OF MY BOARD