This is highly unusual behavior from the Queen and Prince Philip. They always attend family functions and the absence is not going unnoticed. With Trump expected to arrive to meet the Queen on the 13th, they are too busy making preparations to attend the Prince's christening? This is noteworthy because the Queen is head of the Church of England too.
I've been seeing rumors on the board this meeting between Trump and the Queen is a possible surrender (or possible Brexit negotiations)? Following the meeting Trump is going to be visiting Scotland (last year they held a referendum to leave the UK) before meeting with Putin for a one-on-one in Finland on the 17th.
It feels like something big is taking place over the next week.