The article tells you what love is not: It is not a long-lasting, continually present emotion that sustains a marriage; it is not the yearning and passion that characterizes young love; and it is not the blood-tie of kinship.
If you are willing to keep reading after that, and if you are willing to believe the the chemical composition of love, you will find Fredrickson likes to call love a nutrient. If you are getting enough of the nutrient, then the health benefits of love can dramatically alter your biochemistry in ways that perpetuate more micro-moments of love in your life, and which ultimately contribute to your health, well-being, and longevity.
Describing love as a "micro-moment of positivity resonance" seems like a buzz-kill.
Yup, a dash of realism. But the article is interesting. If you find that you only "fall in love" in bed (that is the initial sense that love might be happening, the falling part) then this article might be interesting.