@Tavi & TMC - Thank you both so much for understanding what I meant, and not thinking I'm totally out of my mind!
The Jason development, I'd describe as that before he was a kitten - and now he's a full-grown cat.

(I always think of Plushy as a cat, and that's not only his being able to land on his feet - it's how I came to really "understand" him, I think. Sometimes a cat can be in a playful, friendly mood - sometimes they're in killer/stalker mode. But a cat is always and foremost
itself.) Jason's always been a showman - he's always had the things that I value in a skater (and the reason I'm a Jason fan): Charisma, Personality, Presence. Now that added feline assurance, and... chills.

(I've completely lost count of how many times I've now watched that Sam Smith program - and I didn't even think I cared for it that much the other time I saw him skate to it. In fact, it was Tavi's remark about there being something different about Jason that made me feel curious enough look it up - until then, I'd thought "Oh, not Canned Heat then?" in disappointment, and not felt in any hurry to watch it. Little did I know... )
ETA - Tavi, that is
exactly what I meant! Then, as an uber, if I may...
https://www.youtube.com/watch?v=kkhn4KbisJc
ETA 2 - TMC - I think lots of skaters have "maturity" - but "feline assurance" very, very few...