LEGAL SELECTION CONTEXT

Sample is here: http://jsbin.com/avowu/edit
Core of the issue is here :
// context is correctly reported by jQ
$("[name]", document.getElementById("people")).formula( log ) ;
// context is reported by jQ as HTMLDocument ?
// selector is prefixed with context
$("[name]", "#people").formula( log ) ;
Is this "by design" ?