Bonuses from your Breath of the Wild backup to Zelda Tears of the Kingdom
If you have played Zelda Breath of the Wild on your Switch before you start Zelda Tears of the KingdomBut you should know that you can pick up a few items from one game to the next. There's nothing absolutely essential, but they're still nice little bonuses.
You can get your horses back from Breath of the Wild
The stables of Zelda TOTK contain all the horses from your BOTW backupAs long as the saves are on the same console. Go to any barn and ask to remove a horse (even if you haven't captured one in TOTK yet). The manager will offer you your past mounts. If Epona was part of it, she will be there too.
The photo of the Prodigies
By completing the Zelda Breath of the Wild DLC, players received a photo of Zelda and her Prodigies that they could frame in their home in the village of Elimith. If your console contains a savegame with the completed DLC, this picture will be present in Zelda's house in d'Elimith in your Zelda Tears of the Kingdom game.