When you select a person's name or picture in, you can find information related to them on their profile card. The profile card is also sometimes referred to as contact card or people card.
This feature is available to Office 365 Subscribers only.
What others see on your profile card?
Contact information including, email address, phone number, IM address, and office location
Organizational info, such as who your manager is, select Show Organization to see the organization hierarchy.
For Outlook for Mac build 16.25 and higher, users can see the new profile card. This is available only to Office 365 subscribers with Office365 mailboxes.
Users who are on build 16.24 and lower see an old version of contact card seen below: