It's a beautiful question. As one remark, I remember going to the exhibit of Cezanne and Pissarro several years ago and being struck by how often Cezanne blocks the viewer's way into the paintings; there are often obstructions, obstacles.
So it's interesting now to see, in the still life you quote, how the glass placed front and center blocks the view; how the knife is placed with its blade outwards, towards the viewer; how the bread in turn steadies, or blocks, or perhaps even traps the cloth from falling off the table; the combination of storm and order.
I don't know Melendez but what orderliness, by contrast: everything arranged nicely on a plate, the glass off to the side, all the food ready to eat (no shallots) and tastefully arranged, the cloth spread flat beneath. Even though the rest of the room is obscure in each case, it's clear the scenes are completely different.
Less relevant here, but worth mentioning, is the linguistic difference between "still life" and "nature morte."