Think of a row of things laid out from best to worst, with your finger resting on the second one. Something above it is better; everything below it is worse. The position itself is not bad — it beats the whole rest of the row. What gives it its flavour is the one thing standing next to it: while the top one is in sight, the second one looks like a stand-in for what you could not have. So as a description the words just report a place in the row, and as a thing they become the one you settle for.