If there is no gamepad under someone else's live room on the WeChat video number, it may be caused by the following situations:

1. Platform restrictions: WeChat video number may have different restrictions on different live events or live rooms. Some live events may not support the gamepad function, so you can't see the gamepad buttons under the live room.

2. Account permission restriction: The gamepad function may require specific account permission to use. If your account doesn't have the corresponding permissions, you can't see the gamepad below the live room.

3. Device or version problem: The gamepad function may need to be updated to the latest WeChat version or displayed normally on a specific device. Please make sure you use the latest version of WeChat and check whether the device you use is compatible with this function.

If you are sure that other live broadcast rooms can display the gamepad normally, and your account has normal permissions in other aspects, it may be that the gamepad function is not turned on in this live broadcast room or the activity itself does not support this function. In this case, it is recommended that you contact the live room administrator or the event organizer for more details.

Please note that the above answers are for reference only, and the specific situation may be different due to the update or change of WeChat platform. If you have further questions, it is recommended to directly consult the official customer service of WeChat or consult the relevant supporting documents of WeChat to obtain accurate information.