What is the difference between the two?
It may boil down for why you read, but this is really not what makes character interesting to me.
An otherwise stoic character who shows little to no emotion is nervously shuffling feet? This either breaks the character (and immersion) or speaks volumes about what’s coming next. Of course, this could be described as “uncharacteristically nervous”, but if we don’t even know what is characteristic of a character, such a description will not work.
Language is a set of tools, and good writers wield all of them.
It could be just described as "nervous" which is not at all in contradiction with stoicism. Internal state and what people show is not the same. The uncharacteristically is not present in descriptive version either, no reason to add it here.
Whether the character is shuffling feets or have different tells is just a detail - effectively just synonym of nervous. Anyway, real world people don't do that, you usually notice different voice, speed of talking and subtle differences. It is a bit offtopic maybe, but shuffling feets is a bit distracting exmple because people nowdays don't do it.
Just telling that emotio where it fits is one of tools that can be used.
Varied descriptions are what makes a character. There’s a huge difference between “shuffling feet” and “clenching jaws”, for example.