The gift card was in the body of the email
A 2021 report said people were taking gift cards from large numbers of inboxes. That headline did not name one gift card brand. The gift card was written in the email body. People have taken those gift cards in volume. Before the money is spent, it does not pass through a plastic card or a store shelf. The gift card can already be gone from the email before the recipient opens it.
The film, the receipt and the shelf do not describe this
An intact film does not show whether someone opened this email. The amount on a receipt does not show whether this email's inbox is still yours. A package that someone touched on a shelf is a different path. That path is about the package and the sleeve, not the body of an email.
Reading the gift card over the phone is a different path
When someone on the phone asks you to read the gift card out, you are handing that gift card to the person on the phone. Gift cards taken from inboxes in volume were already written in the email body. Both paths move the gift card away from you, and the two paths are not the same. The phone path is in when someone tells you to buy gift cards and read them out. This page does not describe how gift cards are taken out of an inbox.
Those gift cards were taken in volume inside the inbox. If you are holding only a plastic card, that card does not match the email path. An intact film, the amount on a receipt and a package on a shelf do not say whether the gift card is still in that email. Once the gift card has left the inbox, the plastic card still being in your hand does not change the fact that the gift card has already left.