Yes be careful to conceal the exact angle with perpective trickery.
But leave it plain enough for the judges to be able to ascertain the record breaking nature of your placement.
Here. Look at what happened when I placed a bass guitar exactly 2 ft and 18cms away south east from a three-quarters-destroyed bottle of Southern Comfort, with keyboard still delicately placed on that ledge in harmony behind it:
The results, I'm sure you'll agree, were almost beyond description..