Ensure screenshots use uniform naming conventions across components

[akeller]

Identity screenshots include user "Bark Barkins." This should be aligned with our other screenshots and test/demo users.

Additional note: I thought we had documentation on what to include or not include in screenshots, but I can't find it on this page. FYI @christinaausley

(Edit by Christina below)

Need to:

### Tasks
- [ ] Determine demo user name for screenshots.
- [ ] Add to WCoE/related guidelines.
- [ ] Notify teams of requested change to screenshots.
- [ ] Ensure screenshots are updated, or teams have issue in their backlog.