That looks like the procession from when she arrived from Scotland. That was at night and apparently the Queen had asked for the hearse to be illuminated so that her casket could be seen if it was dark. That night she was received at Buckingham Palace by her family. The next day she was moved to Westminster Hall for public viewing of the casket.
ETA: Here's an article where you can see that the hearse arrived back in London at night.
https://archive.ph/miYdg

That looks like the procession from when she arrived from Scotland. That was at night and apparently the Queen had asked for the hearse to be illuminated so that her casket could be seen if it was dark. That night she was received at Buckingham Palace by her family. The next day she was moved to Westminster Hall for public viewing of the casket.