The more insidious part of this tweet, is childish, petulant, jealousy.
The man-child Obama knew very well that the Queen would be offered this throne during her tour. Therefore, he decided to 'scoop' her by doing his own picture of sitting on the throne.
Of course, she declined by reason of dignity, whereas Obama in his childish mind, takes this stuff very seriously, and and would never 'decline' to sit on the fake throne of swords of a psychopath murderer. In fact, he would relish it, like a fevered fantasy of a child playing Dungeons and Dragrons.
That is all the difference between mature adult class, and a dope smoking, gay, street grifter.