Hmm... I had to google that. "RICE" comes to us from the car enthusiasts as
Race
Inspired
Cosmetic
Enhancement - the addition of non-functional but cool seeming features (almost any spoiler or visible air intake on a production or "stock" car "racing" stripes, exhaust features that make it louder instead of quieter, etc) to a car to make it seem "faster" even though it's not actually faster. If that's not what you meant, please ignore the rest of this post.
There are some desktop screenshots on the wiki at
https://wiki.tinycorelinux.net/doku.php?id=wiki:screenshots although I think they are all very outdated as the wiki wasn't fully operational for a longish time and only recently was fixed.
Since Tiny Core is all about "have it your way", I guess you could say a lot of what Tiny Core users do might be considered "ricing" although there are those who would argue that what might appear to be simple cosmetic changes often do in fact impact performance (either positively or negatively).
While running one of the "heavy" desktop environments might make one's system look (nicer, flashier, more modern, whatever), it likely would make the actual operation of the system slower to run applications (though possibly not noticeably so, due to resource usage) while making it faster, from a user's POV, to carry out common tasks. Running a lighter DE or even just a simple window manager might have the opposite effects... but which one, if either, would be considered "ricing"?