Nice catch (NPI)! Unfortunately I think it's a bit more mundane, it'll be a piece of ice breaking off the lower section of the body. If you scrub through the footage, particularly earlier in the flight (e.g. 1:43:37 on the SpaceX stream, T+54:05) you'll see other pieces of ice flying off that look very similar.
Nice catch (NPI)! Unfortunately I think it's a bit more mundane, it'll be a piece of ice breaking off the lower section of the body. If you scrub through the footage, particularly earlier in the flight (e.g. 1:43:37 on the SpaceX stream, T+54:05) you'll see other pieces of ice flying off that look very similar.