Use Case: The user is shopping in the Shopee app.
Problem: While browsing, the user unexpectedly receives a pop-up notification thanking them for participating in “flash deals” that have ended. However, the user did not take part in any such event or any sales campaign. The message is unclear, it tells the user that they took part in something without their awareness or consent. It leaves the user puzzled as to why it was shown and whether they need to take any action or check details related to the event. This unnecessary interruption disrupts the shopping experience and creates uncertainty for the user.
Annotated screenshot:

Shopee
Best Practice: On Shein, the shopping experience is smooth and user-friendly. The platform is designed to keep the focus on browsing and purchasing, without the disruption of unexpected pop-ups. Users can enjoy a hassle-free shopping journey, where they can explore products and complete transactions without interruption.
Shein