I used people web part in the SharePoint online to show up users pictures and there title. One user doesn't pulled his picture. When I checked it from user profiles, I saw his picture in the SharePoint admin center.
Could you please check the same photo is appearing in user properties.
- Navigate to Admin Center
- Click User profiles on left navigation
- Under People, select Manage user Profiles
- Search for that user using search option
- Select the User and click item menu and choose edit user profile
- Under picture category you should see his current picture
- If not, then download the current image from Delve and upload it here
- Then give 15 mins to get reflect over the sharepoint
- then use the people web part
I had a similar issue, request the user to sign-in to the SharePoint Online and access there Delve profile. It did the trick for me. Although I cannot find more information about it it seems that there is some sort of initialization that happens when the user signs in first time into SharePoint/Office Online.