Sometimes, however, people will come up to an unmanned table and start perusing the wares. The action is non-hostile, and the browser is unlikely to be planning a theft. Every neighboring tabler, however, will keep an eye on them just in case.
If you're an Artist Alley customer, keep this simple rule of etiquette in mind: if someone's not behind the table, you can look at the merch, but don't touch it. You can check it out in more detail when the person manning the table returns, and in the meantime, you'll lower the blood pressure of the table neighbors immensely.
Rock on, guys, and never stop drawing.