We had earlier seen about the steps required for configuring social network accounts such LinkedIn, Facebook etc. in Outlook 2016 & Outlook 2013. If a sender has photos linked to their social network account then it is displayed in the email message header section as shown below.
But if you do not want to display the photos and save some space then you can use the option available under Outlook options to turn off the feature.
Click the File menu and select Options from the list. In the Outlook Options window, click the People Options.
Then navigate to Online status and photographs section and un mark the checkbox with caption as Show user photographs when available. This change would get reflected after restarting Outlook 2013.