Tesla did not manufacture many model X’s in 2021. Some of the model X’s made at the end of 2020 received 2021 VIN’s. They were the vertical screen legacy version.
It wasn’t until late 2021 that the refreshed model X was produced. I thought that the very first ones had 2021 VINs, but I recently heard that no, the refreshed cars started with 2022 VIN.
There are a lot of changes in the refresh. The one that first comes to my mind if you can’t see the interior is whether it lists that it has ventilated seats. There were no ventilated seats during that general time frame in the pre-refresh model X’s.