Force constraints on natural frequency analysis

I've made a simple support structure on which about 150kg load is applied and the structure is attached to other frames.

I did natural frequency analysis (modal analysis) on the structure itself for constrained condition with displacement constraints to the frames.

I was asked whether I included the force (150kg) on the structure for the analysis.

I thought any external load would not be considered for natural frequency analysis.  Anyway, I ran the same analysis with the load on top and I got the exactly same result.

Did I do something wrong?  Or external load wouldn't matter for the analysis.

Also I see gravity load on the tap.  What would be the effect on the analysis by applying gravity load?

Thank you in advance!