I was a chef for a long time. I never had a problem with people photographing my dishes ( or giving out recipes for that matter.) People may have been inspired by the dish but it is impossible to exactly recreate a dish from a picture.
I have done it myself, when I was traveling and had a particularly interesting dish. I do think its a little weird as a diner when someone at a nearby table repeatedly takes pictures of the bread basket, their beverage and everything else that crosses the table.