The shadow cast by the tarp suggests it's opaque, not transparent (or even translucent, really.) Combined with the horizontal lines across "plane", it all suggests a weather-beaten opaque tarp that's been painted to conceal its contents and confuse any overhead photographers.

Could be, but the shadows and taxiway lines line up perfectly. That would require constant shifting of props to maintain for 3 full days (this is 101 stuff for GEOINT folks).

It's also important to keep in mind that spy sats get far better resolution than this publicly-released image would lead you to believe.

No- there would be a solid shadow down the right side of the structure (look at the right side of the bigger hanger in the zoomed out image).

The simple explanation for the shadow is that they left the solid end (wall) of the structure up. (They're often made of a different material like aluminum, or are otherwise more difficult to disassemble due to doors or other things mounted to a semi-permanent wall.)

(ETA: If you look closely at the very top of the shadow, it appears to be a fabric/tarp wall that is sagging slightly at the peak and not attached at the very top of the arch. You can see the shadow of that portion of exposed arch/ frame pretty clearly above it.)

Having the painted-on jet shadow match the actual time of day shadow I suppose is doable if they wanted to deceive a specific satellite passing overhead at a known time, but I doubt it, since it got seen multiple times over at least 3 days.

Missed opportunity to portray something disk-shaped, if so.

Agreed, from this vantage point you couldn’t tell the difference.

That was my first guess. Its not like we don't mess with our adversaries. Why did I think this? Because that's what I would do if I worked there and could.