Absentee ballot processing requires that each ballot is opened, signatures verified, and ballots scanned. This is a labor-intensive process that takes longer to tabulate than other forms of voting.
I have seen a lot of videos over the last month but I still have not seen a video of anyone doing this.
The videos I have seen of absentee ballot processing consist of someone opening an envelope, quickly pulling out the ballot and dropping the envelope without looking at it, checking the top of the ballot to see who it was for and then carefully putting it in one of several piles.