If the seller would put the shaft on the butt and hold the butt down on the table while rolling it and then shot the video of the shaft, this would help as then you could see if all stay straight through the butt, through the joint area and up through the shaft to the ferrule.
If the ferrule stays nice and flat, I would call it a little taper roll. However, when doing this, the ferrule may come off the table. It may just need a facing or it would be an obvious warp. Not to long ago, I purchased a Schon for $ 500.00 and when I rolled the cue when put together, the shaft came off the table 3/8 of an inch and the description said the shaft had a minimal raise in it. Thankfully, it was an ebay purchase and a no brainer for them to refund me.
However, trades can go south when this happens on a new cue I sell and I receive this type of situation I explained. I recently done a trade on a Jocoby with an az member and he sent me the cue ahead of time to look at. Not the common practice, but, as you can guess, the cue was straight as an arrow and I have the highest regards for the member.
If you like the cue and have concerns, there is some members here who do the transaction for you. Both of you will pay maybe $ 20.00 each, but, the cue will be checked out before your money is gone for good.