How does FSL return the variance explained of ICA components it constructs if ICA does not find variance?

I have used fsl’s MELODIC in the past and I remember it telling you what the variance explained of each returned component was. But now that I have taken a deeper dive into ICA I see that ICA cannot tell you variance, after all it is maximizing non-gaussianity of the components.

I could not find this feature explained in the documentation of fsl’s ICA algorithm: