new portrait borders on champion page?

After today's update, when you go to your champion page in your profile, some champions will have a border on their portrait.

I have it on Vel'Koz, Jayce, and Nocturne. But I've played Xin, Thresh, and Leona far more than Ive played nocturne.

So does anybody know exactly how you get these borders? or what they represent?