Caring for Bliss

I've been thinking that when I listen for metta in metta meditation, I can also listen for bliss in mindfulness of breathing. 

Along comes a study about bliss:

"...caring for bliss enhanced the effect of high self-compassion on flourishing and compensated for the effect of low mindfulness on flourishing. Caring for bliss also buffered the effect of low mindfulness on depressive symptoms." (Source)

I'm not sure what they mean by "caring for bliss", except that you notice bliss.