In various night shots out the office window you will see the capitol dome off in the distance on the upper right hand side of the picture windows. The ship, USS Barry is on the bottom left more or less where it should be. Episode S08E01 shows this at 12m10s. Ziva walks into the office and Tony greets her. Picture window in the background.

In reality, the NCIS HQ building faces south, and the dome is off to the north behind the building. It would never show up through the front window.