Meaning:

“看电视发微博,” or “chatterboxing,” refers to watching a program on television while talking to others about that program online, normally via a social media platform. Psychologist Corinne Sweet says: “Wanting to communicate with others when you experience emotions such as sadness, entertainment, fear or awe is a part of the human condition. As television often prompts these feelings, it is not surprising that more of us are taking advantage of evolving technology to share our thoughts.”

Example:

A: 最近这一个月，很多人一边看欧洲杯，一边在微博上评球。

Zuìjìn zhè yígè yuè, hěnduō rén yìbiān kàn ōuzhōubēi, yìbiān zài wēibó shàng píngqiú.

Last month, a lot of people were talking about the European Championship on their microblogs while watching it.

B: 这就叫“看电视发微博”。

Zhè jiù jiào “kàn diànshì fā wēibó.”

This is called “chatterboxing.”