I thought a lot about the potato scene, as well. In one review somebody says that Jack can't keep his eyes off Ennis, even though he is trying to seem to be concentrating on the potato. Maybe it's that: The beauty of the scene is, that we are expecting Jack to turn, slide his eyes, but we can see, in the way he is concentrating on the stupid potato, as if it were a mantra, how much rather he would look at Ennis. When we see it like that, the scene becomes an incredibly potent image of forbidden love/lust. Objects (potatoes and others, shirts for example) become laden with significance, they would not otherwise have, if this love/lust could express itself openly.
monicita