It appears that he has something else vegging in his tent so the tent is out but since temperature and humidity ranges and air flow are very important to proper drying I do not know if they would be more easily controlled or harder to control in a tent. I have never really thought about it before but at first thought I believe there would be more negatives to it than positives, at least unless someone went to the effort to make sure their setup was spot on.
You want to keep the humidity between 45% and 55% and in an enclosed area where the drying plants would be putting off moisture into the air adding to what would already be there it may be difficult to stay within that range. At humidity levels lower than 45%, the marijuana will dry too fast and the taste will suffer. At humidity levels higher than 55%, the marijuana will take a long time to dry, and it will be prone to mold.
Also in an enclosed area that would not get good airflow you may have trouble maintaining the proper temperature range. Conditions should remain constantly somewhere between 65-75 degrees F. At temperatures lower than 65 degrees drying time will be lengthened. At temperatures higher than 75 degrees, the heat will cause the outer portion of the bud to dry quicker than the inner part, and the taste will suffer.
The area where the drying is done should be dark. Light and high temperatures (higher than about 80 degrees) will cause THC to break down into less desirable chemicals, this will lower the potency of the finished product.
Maybe it might be easier to maintain the proper conditions in a tent if it were available for use for drying, I just do not know. I just tend to think that would not be the case though.