Something like you described is a good example!! When children first start with us or are at the age of being taught to put toys away, we will obviously praise a lot because they are still learning what is expected of them and praise is a motivator. As time goes on, and/or they get older, we will start to decrease praising every single time they do this action, as it just something that will become an expectation of them when they are done with something. Perhaps that is what mom has in mind when she asks too praise less?

From what you said in your praise, I assume the child is older? Maybe mom already expects cleaning up toys and doesn't feel the extra praise is needed anymore?