The Supreme Lord, the Supreme Personality of Godhead, is always fully satisfied in Himself. Therefore when something is offered to Him, the offering, by the Lord’s mercy, is for the benefit of the devotee, for the Lord does not need service from anyone. To give an example, if one’s face is decorated, the reflection of one’s face in a mirror is also seen to be decorated.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
नैवात्मनः प्रभुरयं निजलाभपूर्णो मानं जनादविदुषः करुणो वृणीते । यद्यज्जनो भगवते विदधीत मानं तच्चात्मने प्रतिमुखस्य यथा मुखश्रीः
naivātmanaḥ prabhurayaṃ nijalābhapūrṇo mānaṃ janādaviduṣaḥ karuṇo vṛṇīte | yadyajjano bhagavate vidadhīta mānaṃ taccātmane pratimukhasya yathā mukhaśrīḥ
SB 7.9.11