Witness the feeling itself as just a pattern of energy. It has no intrinsic meaning. It's like a sensation in your knee.
This quote is an example for what´s called "One Taste". One Taste is a name for one of the later stages of Mahamudra meditation.
One Taste is ...
when you experience sadness no other than a sensation in the knee.
when you experience anger no other than affection.
when you experience embarassment no other than a sneeze.
Is that possible? Desirable?
Is "One Taste" possible?
It is possible - I can, to a degree, confirm. Once I have adopted a particular perspective, or view, sadness - as example - can appear in the same "space" or "condition" as an itch in the nose. It is then an appearance like all others, without any attached story (that I believe in or attach to).
Thus, one can be sad without suffering from being sad. It is, in a way, similar to an experience I had during a psychedelic ceremony, where I was watching myself having all appearances of sadness without being sad in the normal way. In both cases, I suppose, the sense of being a Self is reduced.
Is "One Taste" desirable, or a loss?
That depends on the context, and the interpretation.
For example, some people will experience a loss of intensity of emotion to a degree that they feel they need therapy. But these are exceptions, even if there is currently a wave of putting health warnings on meditation (something that the meditation teacher Culadasa called "toxic meme" of the dark night of the soul) .
One Taste is, on the other hand, very useful because it diminishes reactivity. If, for example, there is anger coming up, and I recognise it as appearance, I can experience it without a need to act on it. Why should I? There is no need to act attached to it. It´s just a phenomenon like all others. Sounds strange... and of course, does not always "work" like this. But more and more it does. It´s hard to provoke me.
The domain of freedom
The promise of "One Taste" and, related to it, Equanimity, is that it provides a great degree of freedom. In modern language, one would say that we are much less reactive to our triggers.
As Sam Harris sais in another meditation on reactivity:
Witness what is arising, before you react