habits put a picture on desk

I have a habit of always put family pictures on my desk. It was not just me who put family pictures on the desk, almost most of the people I've visited have always put a picture family at his desk. Is there a relation between motivation with family pictures on the desk, I do not know because there is no  survey that shows the correlation, but when I look at pictures family at my desk, and reduced fatigue in my work feel no motivation to do better