What does it mean to send a message to others on WeChat, saying that the bell has rung?

Wechat has set the Do Not Disturb message, and that icon will be displayed.

Click on the friend's avatar, send a message and enter the chat window;

Click the icon in the upper right corner to enter the settings, and then turn on the message Do Not Disturb switch;

Open the message and don't disturb it. When the other party sends a message, WeChat will not prompt. If you want a hint, just close the message and don't disturb it.