Both Rainbow and Bulk were quick to bow before their Princess. Neil didn't know what he was supposed to do. He didn't want to bow to the monarch of a foreign country, but this was an official meeting. Also, given Equestria's position on Alicorns being royalty by default, was he required to bow? After glancing quickly between his companions and Celestia, who watched all three of them, he shrugged and gave her a slight nod.