In "Word Focus" Glenn McClure writes:
Although one should serve to bring honor to God, there are many who are only rendering eye-service. This word “denotes service performed only under the master's eye . . . diligently performed when he is looking, but neglected in his absence” (W. E. Vine). Service that is rendered only when the master's eye is fixed on the worker stands as a reproach before fellow-workers, especially if that one is a Christian. This problem has always existed, especially if the service is of an involuntary nature. Faithfulness to perform only when under observation is a disgrace. One should be bound to perform his work with such faithfulness, not only because he is being watched by man, but because he is always being watched by God. Also, many perform so as to be menpleasers. This Greek word signifies a striving to please men. It designates “not simply one who is pleasing to men . . . but one who endeavors to please men and not God” (H. Cremer, Biblico-Theological Lexicon of N.T. Greek). The object of the Christian worker is not to please men but to please and honor God. If service is rendered with this attitude, the service itself will stand as a testimony to the worker's religion.
Source: Building Christian Relationships: Adult Teacher's Insights, page 22.