I am surprised to have seen no media comment on why the old German is meeting the Queen in Scotland and not in England. Is it merely because she is on her annual vacation at Balmoral? I think there may be more to it than that. The Palace and her government are aware that she is monarch in Scotland and in England but in England she has a role denied to her in Scotland. South of the border she is the Supreme Governor of the Church of England. This is the title of the monarch ever since Henry VIII broke with the bishop of Rome's claims to universal ecclesiastical supremacy. In Scotland H.M. is merely a member of the Presbyterian Church of Scotland. This was one of the strokes of genius of the 1688 Glorious Revolution which removed James II out last RC monarch.
So meeting in Scotland, two heads of state come together. If they were meeting in England it would not be so easy to hide their contrary claims over Christians. The media and Joe Public are either ignorant of this or chose to ignore its significance.