The Habsburg eagle had two heads, an imperial crown, and a sword and orb in its talons. The crown on the Austrian eagle's head is a civic crown - it looks like battlements, and stands for the burghers of Austria, as the hammer and sickle in its talons stand for artisans and farmers. These arms, which were adopted in 1918, also include a shield on the eagle's breast bearing the arms of the House of Babenberg. The broken shackles were added to the Austrian eagle's legs in 1945, andrefer specifically to the liberation from the Nazis. I found that landlocked Austria possesses a war ensign.
Proportions are the same as for the civil and state flags.
I had to eyeball the position of the shield for my GIF but the result looks about right. According to the law, this is not an army flag. Be h the height of one stripe, the height of the shield is equal to 1,3 x h and the length equal to h. The shield is of XIXc French style. The bottom of the shield is on the middle of the white stripe.