Signify? That is completely up to you. We provide quantitative analysis tools. Qualitative interpretation (that is, "science") is the user's responsibility.
What is it you want to do? You will have an output dataset from the 3dpc run, each sub-brick of which is a spatial component. You will also have a bunch of 1D timeseries files, each one of which is a temporal component. You can look at these using the usual AFNI tools -- the AFNI GUI for 3D datasets, and then graphing the PC time series as an overlay 'FIM Ideal' in the dataset Graph window, for example.
But how to interpret the results in terms of the brain? That I can't tell you.