One way to import photos in mass into CA Directory by using the "dxmodify".
Please look at "Reference > DXtools > DXmodify Tool Add New or Changed Information to a Directory".
Here is a sample, tested with IM r12.5.16 and Corporate User CA Directory r12.0 sp12 based on a neteauto OOTB sample:
"dxmodify -h MyDirSrv -p MyDsaPort -f MyFile.ldif"
MyFile.ldif contains lines as following:
jpegPhoto:< FILE://c:\photos\ User02.JPG
With this sample the "jpegPhoto" attribute has been populated from jpeg files with the matching binary data for the 2 users: User01 and User02.
On IM side, Photos are "Separator" Attribute Name fields with "Picture" Style in IM screens.
Such fields deal with Binary Attribute Names which are the physical attributes that contain binary data (jpegphoto is one e.g. of such attribute)
If you plan to implement user photos on your IM environment please check that your IM directory definition (Corporate User Store Directory.xml) include mapping to such attribute.
These fields’ contents deal with Mime types. e.g.: gif, jpeg.
For some additional information see: "User Console Design Guide > Configuring Profile Tabs and Screens > Additional Components in a Profile Screen > Add a Binary Attribute or Picture to a Profile Screen".
The physical attribute here is jpegphoto.