These are the tea-leaves which make that fresh tea for you. Its the smallest and freshest leaves that are picked, dried and grinded before it is processed and packaged. Tea plantations on a commercial scale started during the days of the British Raj. The British had made huge investments for the production and transportation of tea. The job of picking tea leaves is still done manually - yup, you have to choose and pick the smallest leaves by hand with a heavy basket hanging down your back.
So the next time you sip your tea, remember where it comes from :-)