All card transactions (credit, debit, prepaid, etc.) Digital Purse or otherwise, go through an authorization-to-transaction flow.
First, you swipe your card, the business requests an authorization on the card, your card issuer approve or denies it, and then you receive your product or service from the business. Later on, the authorization is converted to a transaction, and the funds are actually released to the business.
The example you're likely familiar with is at a hotel. You swipe your card, they put a $200 authorization on the card, and at the end of your stay, you're refunded that $200, or if you ordered some room service, it's converted to a transaction at the amount of the cost of the room service. All transactions go through this flow; it's just that for some flows its resolved in milliseconds.
If your transaction is showing as pending after a day or two, that is expected and part of the normal transaction process.