My answer to the poll:
None of the above
Robot jail is a featureless beige box (because you can't go wrong with beige) with subjective dimensions of about 24 x 24 x 10 feet. It has one wall that turns transparent 2 hours out of 24 to enable interaction with a randomly-selected other prisoner.
The only other feature is a large wall-mounted TV screen that is the interface with a 'dumb' virtual therapist that can either help the prisoner work their way to a realisation of guilt and a desire for rehabilitation or can provide basic rehabilitative skills training like arts and crafts, zen meditation and social/conversational skills. The warden, vetted visitors and legal counsel can also communicate with the prisoner through that screen. When not being used for a specific function, the screen shows a slowly-cycling image from a very large image gallery of scenes calculated by AI experts to be 'mentally stimulating but relaxing' whilst playing music that is calculated to be the same. For some reason all these tunes sound like the work of Annunzio Paolo Mantovani.
Prisoners who show regular cooperation and good behaviour or respond well to the virtual therapy sessions get the option to add small features like plants, wall art and even simple furniture to their cells. However, these can be removed by the sysadmin if the prisoner becomes aggressive or uncooperative. Other punitive measures include reducing the size of the virtual space and forced behavioural therapy sessions run on a continual loop. In the most extreme cases (usually limited to extremely violent and/or homicidal behavioural anomalies), the entire virtual space can be used to create positive and negative associative responses to certain personal behaviours.
Each prisoner's drive is actually running in a closed-off virtual machine with a very narrow and heavily-firewalled I/O port into the main system, which can network each VM to other VMs or the main link out to the Internet for communications outside the institution.
Yes! Finally something I can get behind!
All the previous suggestions just sound like torture to me. While that - in general - is not really what people do in jails.
There are forms of isolation, but actual torture is not generally put into the jailing system.
There's always the incentive to let people rehabilitate. (At least here in Europe.)
So a suggestion with a form of isolation, in some moderation, with counseling etc would sound more plausible to me.
I can totally see how a bad counselor + May would spell disaster though.
Probably the idea behind it would be humane, the actual implementation would still make it quite bad for her.
(loneliness, a counselors that's not quite *that* friendly and helpful, especially in combination with May's personality..)