The adjective laudatory, meaning expressing praise, describes the expression of praise. Laudable, meaning praiseworthy, applies to the person, thing, or event receiving the praise. For example, a very laudable movie might receive laudatory reviews from the critics.
Compassion is a laudable trait but a disastrous basis for government policy. [Vancouver Sun]
Gov. Andrew Cuomo distributed a laudatory video praising the state accord and legislative leaders. [Hornell Evening Tribune]
Part of the reason for the intense interest in infants was Labour’s laudable desire to improve social mobility. [The Economist]
What troubled me was the suspicion that future museum exhibits would depict the whole shuttle program in laudatory terms, instead of treating it as an foolish diversion of national resources. [Foreign Policy]