Office 365 is a wide service and offers a lot of functionality if you have the corresponding license acquired. So, one frequently asked question is: What happens in Delve if a user has no Office 365 license assigned? See it here.
And the answer is: Delve works for all users in Office 365 (in an AAD). The following user Raul has no Exchange license in Office 365.
So, this user has just one license plan set.
Ok, Now, can the user update his profile picture and his user profile data?
Yes. The user profile data (text) can be modified directly on Delve page. If there's no Exchange mailbox (where such a change happens more or less immediately), the User profile picture must be set in the SharePoint user profile page. We see that with an extra page and the URL path https://<tenant>-my.sharepoint.com//_layouts/15/editprofile.aspx
So, here I uploaded a new profile picture for that user. When saving, the update can take some time - usually up to 24 hours till the SharePoint User Sync writes the updated data into the AAD user profile...
Just to mention: The Microsoft Graph allows to update the user profile picture only, if there's an Exchange Mailbox existing (currently).
Search is mostly faster - here the new user profile picture is already existing.
If a user has an Exchange license, the user profile picture can be changed within the Delve page with URL https://delve.office.com/?u=<someid> as well.
So, hope this short article clarifies this Delve and user profile questions.