In order for Transport for London (TfL) to calculate the best daily charge for you, they collect your journey information at the end of the day, and calculate the total charge for your day's travel overnight. No fare information is stored on your card, so they can't display your balance or travel cost, each time you touch in or out.
Oyster cards are different, as they store and calculate all your fare information on the card itself, so they can display the fare charged and balance remaining as you travel.
Charges should show on your TfL online account the following day, but you’ll be able to see your journey history and provisional charges on the same day as your journey.