Well he does have a point about the 71 it is a little odd to have a LPD attached to a carrier. I see four possibilities. One the PLAN had it there to support helicopter operations. As pops pointed out the photos show a distinct lack of both fixed wing and rotary wing assets in the deck. This might mean that there is some issue with the ship its self and the 71 was used to maintain the helicopters in the CV's stead. I find this unlikely.
option 2 the PLAN are trying to create a duel role taskforce. The idea being that the LPD would in a islands sinario move in for landings well the carrier supports via fixed wing air cover. This would however divide the battle group and potentially weaken overall defense.
option three. The LPD is being used as a stand in for a logistics ship. Its holds are full of rice not troops.
?
option four. She's there to make the picture more impressive. Just filler.
Since Liaoning is by no means operational, this assemblage can only be for the photo op, thus 71 is likely there only to complete the family portrait, ie look impressive.
In actual operation, it seems not inconceivable the 71 would pair with a CV to increase a task force's ability to support ASW helicopters.