I get this indignant foot pecking when I forget to 'trade' a food treat for eggs (or more accurately, get things in the wrong order - one must treat them, then get the eggs).
The boss chicken of our min-flockette watches me collect the eggs. She gets a bit irate, and then runs around in front of me, delaying my exit from the chicken run, looking at me like I've just committed a heinous social gaffe, and then taps me a few times on the toes. Not aggressively, just in the manner of a Town Hall Point of Order. Banging the Gavel, if you will.
One can't help anthropomorphise these situations, but as far as I know, foot pecking is an activity by the chickens to their rooster when he's not doing his job properly. The rooster's job is to find food, check it, then call the ladies to the table, standing aside and letting them have their fill whilst watching out for any danger.
If the rooster wants his way with the ladies, or is just lazing around, and the ladies aren't exactly impressed with his abilities on the cuisine front, they will tap his feet to let him know that he's slacking, or at least not 'doing his job' properly (I challenge any bloke to deny this happens to humans).
The intensity of this activity comes down to the personality of the boss chicken - is she a CEO (mild) or a Union Shop Steward (bloody dangerous)? I mention this because recently our boss chicken passed on - she was a CEO, much older than her staff. Now her second in command has taken on the mantle, and she's a bolshevik.