That black rectangle looks to cover about a 3000 sq metre area as per the 25 Feb image, if it is to continue south east towards that "L" shape road then it would cover about 20,000 sq metres (according to the area tab on planet.com).
These have been refered to as "test" ponds , which I understand are to cover 15 hectares or 150,000 sq m.
This appears correct as the curved ORE ponds further north measure to about 500,000 sq m of area each.
The green circled ORE pond below is about the same area as the GXY black area, we have a bit of catching up to do if GXY needs a similar area of ponds? or does the POSCO or LPD process require smaller ponds??
This is ORE's current set-up;