I saw an article about how rich people build museums attached to their homes. They get a tax deduction from the building costs, and don't have to pay property taxes on that part. They use them for private parties, weddings, etc.
They're supposed to be open to the public, but of course nobody from the government checks into that. The reporter wasn't able to get into any of them.
I'm assuming that's what the "philanthropy wing" is about.