Look—here's a table covered with a red cloth. On it is a cage the size of a small fish aquarium. In the cage is a white rabbit with a pink nose and pink-rimmed eyes. In its front paws is a carrot-stub upon which it is contentedly munching. On its back, clearly marked in blue ink, is the numeral 8.
Do we see the same thing? We'd have to get together and compare notes to make absolutely sure, but I think we do. There will be necessary variations, of course: some receivers will see a cloth that is turkey red, some will see one that's scarlet, while others may see still other shades. (To colorblind receivers, the red tabelcloth is the dark gray of cigar ashes.) Some may see scalloped edges, some may see straight ones. Decorative souls may add a little lace, and welcome—my tablecloth is your tablecloth, knock yourself out.
Likewise, the matter of the cage leaves quite a lot of room for individual interpreation. For one thing, it is described in terms ofrough comparison, which is useful only if you and I see the world and measure things in it with similar eyes. It's easy to become careless when making rough comparisons, but the alternative is a prissy attention to detail that takes all the fun out of writing. What am I going to say, "on the table is a cage three feet, six inches in length, two feet in width, and fourteen inches high"? That's not prose, that's an instruction manual. The paragraph also doesn't tell us what sort of material the cage is made of—wire mesh? steel rods? glass?—but does it really matter? We all understand the cage is a see-through medium; beyond that, we don't care. The most interesting thing here isn't even the carrot-munching rabbit in the cage, but the number on its back. Not a six, not a four, not nineteen-point-five. It's an eight. This is what we're looking at, and we all see it. I didn't tell you. You didn't ask me. I never opened my mouth and you never opened yours. We're not even in the same year togehter, let alone the same room...except we are together. We're close.
We're having a meeting of the minds.