Judging by the image of the proposed interior, my guess is that Trump is envious of the interior of Putin's Kremlin and all the pomp of his long walks with soldiers opening enormous doors for him as he attends gatherings of the faithful to tell them how wonderful Russia is. Trump is on a deadline, he has to get it finished in 3 years so that he can do the walk from the Oval Office to the Ballroom to address his acolytes on camera before his (legal) term or his ability to walk, expires. Imagine how he would feel if the first actual president to use his big beautiful ballroom was a Democrat?
The doing-over of Isengard in the style of Mordor comes to mind.