That’s a place where the cement actually meet, it’s more like a cross, where water settled And calcification. I do home repairs for a living, and if you see the cement squares they all meet in the same place there. But that was a good catch. Just in case. If you look where the cement squares meet corner to corner next to the Q - You will see the same pattern.
so are there other tiles with other letters?
look at the center right section, just below Harry's shoes - there is another mark there, almost looks like the letter T
That is the intersection of the concrete slabs distress cuts maaaaaan
or a plus sign +
Oh, now you did it -
Q +
right in front of the Queen's coffin
Nice. Ok... now what's in William's left hand?
likely the top of a sword
there's no t there. something in the grout but nothing on the tile.
That’s a place where the cement actually meet, it’s more like a cross, where water settled And calcification. I do home repairs for a living, and if you see the cement squares they all meet in the same place there. But that was a good catch. Just in case. If you look where the cement squares meet corner to corner next to the Q - You will see the same pattern.
where the 4 corners of the tile meet it marked with chalk the same thing next to the Q
edit; those are the only tiles marked like that in the picture the other corners appear to be unmarked