Hi Natincr,
After uploading your picture in Office 365 portal successfully, the picture should replicate to Exchange Online, Lync Online and SharePoint Online. However, it may take about 24 hours for the changes to take effect.
To change the Lync display picture, you can also use a public URL for the image. For detailed information, please refer to the following KB article:
http://support.microsoft.com/kb/2497721
Thanks,
Jason Jiang