So this guy recorded the ellipse and noted the heavy rubber pads. He speculates this is the new landing site for Marine One since they are working on the one on the WH lawn. That one is currently surrounded by what looks like a construction fence (plywood to keep out lookie lous). Psaki states that it is simply maintance.

I've watched Marine One land on the lawn of the WH and I can't imagine what kind of maintenance they could be doing when all there is is green lawn. Is there more in that area that would require maintenance for six to eight weeks per Psaki?

Are the good guys changing up the scenery to make it harder to duplicate?

Are the good guys removing one landing zone and forcing them to use the ellipse which is much more exposed to public?

Maybe someone with more idea of what is there could chime in.

Are the bad guys using maintenance fences to keep prying eyes away?

https://www.youtube.com/watch?v=HR8XW8_591g