NYC Mayor Michael Bloomberg has his own tree at Wave Hill
That's why he has that happy look after looking seriously at the other trees on the premises. Imagine - how would you like a tree planted in your honor and with your name on it.
Who's better for this? The tree or you? Besides, he has a billion dollars already to his name and he needs a tree? Fame and power follows you wherever you go and having lots of money seals the deal, even if a tree is the main part of the deal.