The Kush Cakes Facebook post with the box juxtaposed against the Denver banner also included a lot of hashtags:
A search of facebook for each of those hashtags will show the post with that image.
It doesn't prove that there was a Kush Cakes Booth at the Big Industry Show. Only a shot of a booth with Kush Cakes, people, and some indiction that the photo was shot at this year's show can do that.