What you're seeking for is where you're seeking from.
Words are just labels; the true form is in the vibration. Therefore, you’re not going to pin the attributes of ‘kindness’ or ‘compassion’ to the vibration with words in a way that everyone agrees upon. Kindness and Compassion can be both actions and states of being. It is extremely difficult to distinguish between the Middot (energetic emotional body); Kindness and Compassion can be found in Geburah when it adopts those qualities from Chesed, for instance.
This is due to the fractal nature of reality and the all-pervading energy; each attribute with which we would create some boundary around the energy will, by necessity, contain within it all possible variations of expression clothed in that particular attribute of energy; for example, Chesed (Kindness & Compassion) has within it Chesed of Chesed (Compassion of Compassion) and Geburah of Chesed (Strictness of Compassion) and also Chesed of Geburah of Chesed (Compassion of Strictness of Compassion), etc. This is what is meant when it is said ‘it is difficult to distinguish between the Middot’.
Do we understand that our definitions for these labels of ‘kindness’ and ‘compassion’ are not ‘correct’ or ‘true’ in any absolute sense, but reflect our subjective understanding of them? So who can tell of the ‘essential nature’ and ‘quality’ of compassion or kindness, in that case? Where is the language that will shed light on the character of such attributes? Does not Kabbalistic understanding warn of speaking on the abstract form or the essence of anything, since these things, as such, cannot be known in an intellectual sense?
We can agree that, by our experience and understanding, ‘kindness’ and ‘compassion’ are like so and so, but this does not lead us to universal truth, merely a muddle of our own minds in an attempt to create some imaginary schema out of imaginary divisions of character and quality from what has no division or variation whatsoever, except by our own self-created veils which restrict and cast shadows upon what our senses can perceive.
‘Is-ness’ does not exist as a quality, but only as a semantic frame of comparison, and while drawing comparisons may feel useful at times in order to communicate some concept, more often than not such descriptions are mishandled in such a way that, as we see above, it causes no consensus of meaning and intention in what is understood or felt when we consider the expression behind the word ‘compassion’ or ‘kindness’. Such expressions are not best known through words, but felt through our Middot (emotional energetic body), which is what the language of the Spheres is really describing, not some dry and analytical interpretation of the matter.
The energy is one simple, unified light of existence that pervades all things. When we allow this energy to express through certain pathways in our mental, emotional, and physical body, we have a form at the end that we will label one thing or another, but is really just a shade of that everlasting truth.
Compassion in one’s intention may look to some as harshness, because compassion in some instances may be withholding something for the good of someone else, to the best of one’s understanding. Strictness in one’s intention may look to some as kindness, because harshness in some instances may be giving energy for the good of someone else, also to the best of one’s understanding.
But our small perspective cannot carry out or weigh such judgments; unless one has developed sufficient sensitivity to the energetic reality around them, one cannot make such discernments and respond accordingly. In such cases, we should practice humility and annulment of our discernment, recognizing that we do not know and practicing a true honesty. By this honest and transparent living, energy automatically flows to begin working upon expanding the vessel of sensation in order to perceive more subtle layers of existence.