Additional meeting and call-related features and issues within Microsoft Teams for business
Hi @Erin L
As far as I am aware, there is currently no supported method to edit another user's displayed profile photo from your own Teams client. Teams displays the profile picture associated with that user's Microsoft 365 account, and only the user themselves or an administrator with appropriate permissions can update it.
If your goal is to change how a caller appears during incoming calls, Teams does not currently provide a supported feature that allows you to assign custom photos, avatars, or nicknames to other contacts.
The workaround mentioned in other discussions only applies if the caller changes their own profile picture. For example, they could upload an image containing their preferred name or other identifying information, which may then appear when they call you.