2) Marc took these photos of Buckingham Palace during his stay in London Was the Queen at home when he took the first photo? Was the Queen at when he took the second photo? What do you think?

To answer the question about whether the Queen was at home when Marc took the photos, we need to look at the flag on top of Buckingham Palace. If the Royal Standard is flying, it means the Queen is in residence. If it's the Union Jack, she is not. Based on the photo, it's difficult to see the detail of the flag clearly. However, assuming the Royal Standard is flying on the first photo, then the Queen was at home during that time. I can't say what happened during the second photo.