Just to be sure … do we really know it is?
Well, for what it's worth:
1. A civilian/commercial ship typically wouldn't take such a long time to lay the ship's keel - Especially not with Dalian, which isn't just the largest shipyard in China, but also one of the busiest shipyards in China.
Looking back at Copernicus - Using the same period of time for those meager few pieces of the ship's keel/bottom structures to be laid inside the drydock, a civilian/commercial ship would've had pretty much all of its keel + bottom sections of the hull assembled inside the same drydock.
2. The foundation stands/equipment placed inside the drydock indicates that the ship to be constructed and assembled is actually pretty large in size. That 28.67 meter-wide hull structure shown below is a good proof, which is even wider than the beam of the Kirov-class battlecruisers.
And given that Dalian has never built any LHDs, LPDs or any large-sized replenishment ships, I have reason to suspect (or believe) that this is in fact an aircraft carrier under construction.
Well, if this is the same that "should" be 004, then for my taste the bow is not sleek enough and/or rather too close to the wall, so I don't know how an overhanging flight deck is supposed to be added.
(Also
@Nx4eu for this one)
There's no rule which dictates that an aircraft carrier must have her bow pointed towards land and stern pointed towards the water when under construction and assembly inside a drydock.
Case-and-point: Here's CVN-79 John F. Kennedy during her launch ceremony. Notice where her bow and stern are pointed towards while she's still inside the drydock.
But why not placing them then directly in the correct distance to each other?
Because the individual hull module sections would need some spacing allowances to work with before they are ready to be connected together? This isn't an odd procedure.
Kindly refer to
@David78's answer just above. 003 CV Fujian too went through the same process.
Those hull sections and modules can be lifted (using crane, #1), moved (using jacks/guided rails, #2), or floated (towed, #3) into their new positions inside the drydock.
Here's #2 (Braemar cruise ship):
And here's #3 (CVN-80 Enterprise):
In the meantime, @勤劳朴实罗素历 seems to indicate (albeit rather indirectly) that the aircraft carrier's construction and assembly works are underway as well.
