From what I understand, starting on the 23rd at 12pm EST, tbt will do basically what Reese does, offer to buy off the turnip you got from the shop. Before the 23rd, you can buy it, after, it's no longer for sale.
Think of it like a verrrry long Sunday when Joan comes to town. But she's in town now for like a week. Once she 'leaves' Tbt -kinda like Reese- will give random prices above and below market price for you to sell.
The prices changes everyday at midday -for here atleast- and twice a day. You go to the shop to see the buy back price, then go to your inventory to sell it, if you like the price.
My only question is, it said 'hover over', so what do people do who don't have a mouse to hover with?