It is quite an extensive survey. It seems you explored quite a number of
results to compile it, which is great. Also, the exposition is pretty good.
I think the idea of using sketches of proofs instead of actual proofs was a
good idea. You mostly struck the balance of ideas to present and details to
suppress well.

My main complaint would be though that this survey reads a bit as just a
long "laundry list" of what is known about prophet inequalities in
different context. That is, each section is coherent internally, but there
seems to be not that much connection to other sections. The only more
general conceptual technique/take-away message that you highlight is the
thresholding approach. But it feels that more could have been done here.

Still, good job!

Grade: A-