How did you feel when your childhood friend called you up on your birthday after a long time. Weren’t you ecstatic? There wasn’t any need for him/her to gift you or there was not any need of his/her physical presence. The very fact that the person called you, filled you with joy.
Similarly Bhagvan has no dearth of devotees offering service or devotees offering bhog to him . For sure he has no shortage of food. But when we lovingly cook food and serve him, what he sees is our ‘bhav’. What he sees is our desire to serve him.
The bhav is important.
Remember Sudama? How he had just a grain of rice and yet he offered it to the Lord with full ‘bhakti’, with full devotion. And the Lord accepted it. Was he hungry? Did he have shortage of food? No. He just looked at Sudama’s bhav, his bhakti.