Are these photos of a UFO? I wish I could confidently believe that they indeed show a UFO to the right of Nelson but I doubt it because the photos were taken from inside the National Gallery and from behind a window pane. I’m guessing this is some kind of flare effect, reflection or dust on the window. Be that as it may, the photos are pretty simulations of what a UFO photograph should look like.
The photos were taken on Tuesday March 13 in the late afternoon, 4ish I believe.