It's really simple, this is small portable light.

真的很简单，这是一个小小的便携灯。

So for getting depressed in London, I could take a portable blue light with me, and use it for 15 minutes in the morning.

因此当我在伦敦觉得沮丧时，我可以随身携带便携式蓝光，在早上使用15分钟。