They're provided with choices and the character really becomes theirs instead of just being observers of what's going on. (goodereader.com)
It is always implied that there is an observer who is implicit — that is, not mentioned in the account. (religion-online.org)
On two occasions I have been an observer at elections in countries whose authoritarian governments had long excluded all or most of their citizens from any participation in choosing their leaders. (newlawjournal.co.uk)