Maybe this is just my district and my thought process - but the HD is your colleague, not your boss. The leader of the program yes, but not the dictator of YOUR job. You answer to the principal as they are your evaluator/disciplinarian. The HD is also overseen by a principal.
Iím not saying to be an uncooperative employee and disregard everything the HD says - no, not at all. Youíre both there for the greater good of the program. Donít feel pressured to do something silly or seems like a waste of time. Be honest with the HD, and politely remind them that youíve got a job to do, and stacking chairs/stands isnít one of them. Just food for thought...