They are the details of your order. It says you will receive your order on the 22nd. (Despatch Date). Even though it's downloaded.
You will receive the centre part of the birth cert, with all the details on, in black & white, when downloaded.
You should also have what the GRO call a COL number in a conformation email.
Enter the COL number. and 2022 in the smaller box, next to where the COL number goes.
https://www.gro.gov.uk/gro/content/certificates/order_history.asp
Even with PDF's there is now a slight backlog. You may not have the PDF by the 22nd.........even if you receive an email telling you it's ready. But at least you can try on the 22nd.