There are several Active Directory attributes that can contain images. By default, the program adds user photos to the thumbnailPhoto attribute because this attribute is used by most programs (including Outlook, Skype for Business, and Office apps). This attribute allows you to upload images up to 100 KB. If you need to have larger images in your AD, you can change the attribute used by the program.
Change the default attribute settings only if you are sure that the AD attribute that you choose is supported by your applications.
To import photos to a different attribute in your Active Directory, you need to click the Settings button on the toolbar. A new window will open (Fig. 1.).
You can select one of the predefined AD attributes or provide a custom one (it must exist in your AD).
Switching to another AD attribute (as shown above) changes the appearance of the Users and Contacts list. The photo thumbnails displayed on the list are always based on the AD attribute selected in the Settings window (Fig. 1.). If you choose an attribute that is empty in your Active Directory, the user photos on the list will be replaced with the default blank photo avatars (Fig. 2.).