Around your profile picture you can see a frame with stones or gems; the color of frame and the gems, and the amount of gems, will depend on the category that you have reached in the weekly ranking.
For this reason, as you advance to the next category, you will see that the framework changes. To be able to review the different frames and the leagues each of them corresponds, access the Ranking section in the game by selecting the trophy icon in the lower left corner of your screen.
Once you access the section, select the golden trophy in the upper left corner to be able to navigate through the different leagues.
You will also have the possibility to equip a specific frame that can you win by completing the themed missions. To modify your frame go to the Inventory which is represented by a backpack in the bottom bar of the screen.