Severaal reasons.
1) They are conducting formational exercises with large groups of ships for their carrier. They have never done this before and are establishing doctrine.
2) As a photo op for the masses.
3) As a message to other regional nations.
4) To pre-empt the Indian two carrier exercises that occurred on January 4th, getting their message with their images out in front of that.
Now, they are in serial production of their J-15 aircxraft which are very decent and capable strike fighters. Not to be underestimated.
They have already trained one group of pilots on take-offs and landings, and formational exerciese with their three pre-production aircraft available for that purpose.
In December they turned over their first six production aircraft, and will be training those soon.
I expect by the end of the year we will see the Liaoning operating with 12-15 aircraft.
Thanks, Jeff.