Neither the base engine CMANO, nor the DLC ship with any unit pictures.
These must be downloaded separately, as they are quite large files. Also, I think there could be copyright issues if the base engine came with certain company pictures, so the picture packs are community contributed and distributed.
The link to download them is:
http://www.warfaresims.com/?page_id=1876
Please note, there are 2 separate download files. CWDB (Cold War Database covers the period 1946-1979) and DB3000 for all other post Cold War weapons and craft. They are quite large files and overall, done very nicely with just an occasional mismatch. Definitely a must have though to increase your immersion, in my opinion.