A persona allows you to communicate in multiple different ways. However, your default persona will appear on all automatic communication. You can easily communicate using an additional persona by choosing it from a drop-down within your newsletter builder or "share article" button.
Once a profile and brand are completed a personas can be created by going to
Account Settings > Profiles & Branding
Click on the profiles/brand and dragging it to the "New Persona" section on the right.
Watch the video below instructions.