What is the symbolism of a backwards flag when it's NOT on a vehicle or uniform?

There is no implied meaning or symbolism. Flags that are displayed on patches or vehicles are situated so that they appear to be flowing in the wind as the person or vehicle moves forward. A flag that is on display can be situated in any way except upside down. An upside down flag symbolizes distress and/or surrender. It is a matter of perception and custom. We generally see a flag in print or hanging on a wall with the stars to the left. However, when you observe one flying on a flag pole, it could be flying either way.