Set project icon to show 1:1 avatars instead

We use Asana projects as 1:1 docs and I just noticed that two of those projects have a unique visual. Instead of the typical generic project icon (lightbulb, check mark, map, etc) these two projects show my avatar photo and the avatar photo of the other person in the project.

I have searched around and can’t figure out how to set this up for my other 1:1 projects. Does anyone know how to do this?

You have to visit someone else’s profile and it will offer the possibility to create a 1:1 project. But it has to be from scratch.

I am seeing this button removed from some instances. You?

My screenshot is from this morning, not sure if this is being removed or not…