The pencil on your picture
At the top of the tab with your name, your picture has a small pencil on it. That's where you change how you show up in Ideario. Tap your picture, or anywhere on that card, to open your look.
From there, use a photo of you, or pick a look from Buddies, Auras, Geometric, or Emblems. Your look shows on shared ideas and in comments, and it follows you to every device.