Hello Bhim,
I'm Jin, a fellow Windows 10 user and an independent advisor.
Microsoft Account and Community uses different profile pictures. You can update your profile picture on Community by logging in to
https://answers.microsoft.com/ click on the display picture on the upper-right. then select My Profile.
On your profile page, click Edit profile then Change picture. Upload your desired profile picture for community.
As for the Profile pic on various Microsoft app (such as MS Office, Windows... etc), there's really no specific time frame wherein it gets updated. Sometimes, the changes reflects to quick & sometimes it takes really quite some time. However, once you've updated it in
https://account.microsoft.com/ it will eventually get synchronized with the apps your signed in with.
Kind regards.