The image (without the truck) is most consistent with the Naval Jack flown by the Confederate States Navy from 1863-1865. http://confederateflags.org/navy/fotcnavy63/
Very similar versions are often referred to as a 'Confederate Battle Flag' although distinct flags of similar appearance were adopted in 1863 as the 'Army of the Tennessee Battle Flag' (http://confederateflags.org/army/fotcaot/) and a similar pattern on a square field was adopted as the 'Army of Northern Virginia Battle Flag'. Your illustration makes it impossible to see the stars near the center of the flag, so a 'Battle Flag of the Department of Alabama, Mississippi and East Louisiana' (1863) cannot be ruled out.
The best I can say is it is a modern interpretation of the 1863 Naval Jack which has been popularized and sold commercially as a generic ahistorical 'Confederate Battle Flag'.