It sure looks like language use to me

Today we needed to drop of some Mountaineer Magazines at Wholesale Sports. Since Wholesale Sports is a dog friendly store and they're all fans of Ranger of course we took him with us. As soon as we got to the desk where we drop the magazines off he was eagerly looking for his favorite clerk, the one who always gives him treats. When he didn't see her he called for her and the instant she came out his bottom hit the floor and he began repeatedly signing food. She came over and petted him and made much of him and while he soaked it up he continued signing food. She stopped petting him and told him she'd go get his treat. Ranger sat quietly and stopped signing food. It was clear to me that once he'd made it clear to her that he wanted his treat he was content to wait for her to get it. He didn't continue to superstitiously sign he used his sign to say what he wanted and once it was clear he was going to get it he stopped asking. That sure looks like language use to me.