I am intrigued by the mat clearly visible at 5.15.
And again at 7.54 when both the King and Prince of Wales are standing on the mat as the procession passes by them.

Have not yet found any information about the mat and will continue searching.

Link to Order of Service held 2022
https://www.westminster-abbey.org/media/xqqa5frv/order-of-service-order-of-the-bath-2022.pdf