Apasmāra and Naṭarāja - cruelty or kindness?
What passes for ruthlessness and cruelty from a superficial look is indeed a veritable favour when observed keenly! The inexplicable "retribution" for the juvenile's dastardly act of "attempting on the life" of the Person Divine is an act of Saving Grace, of saving the very life of the one who advanced with evil intentions! Says a subhāṣita: What is so great about helping someone who has done you some favour? He who is a benefactor in regard to a malefactor is deemed a true benefactor.
upakāriṣu yaḥ sādhuḥ sādhutve tasya ko guṇaḥ ?
apakāriṣu yaḥ sādhuḥ sa sādhuḥ sadbhir ucyate ! ||
उपकारिषु यः साधुः साधुत्वे तस्य को गुणः ?
अपकारिषु यः साधुः स साधुः सद्भिर् उच्यते ! ||
Also see, Yogacūḍāmaṇyupaniṣad 28.
As a text on Āyurveda says, the doctor performing the operation is not being cruel even though it apparently looks so; on the other hand his is indeed an act of profound kindness.
nidāna-jñasya bhiṣajo rugṇa-hiṁsāṁ prayuñjataḥ |
na kiñcid api nairghṛṇyaṁ ghṛṇaivātra prayojikā||
निदान-ज्ञस्य भिषजो रुग्ण-हिंसां प्रयुञ्जतः ।
न किञ्चिद् अपि नैर्घृण्यं घृणैवात्र प्रयोजिका॥
The attempt to murder is considered in Law as a more serious offence than the act of murder itself ! Here is a shower of mercy upon one who by design and intention sought to vanquish and exterminate the very Lord!
Touching anyone with one's foot is construed as ill-mannered and contemptuous especially if done consciously; nevertheless is here an act of "bullying and cowing down" an opponent, yet helping him ultimately in the ultimate sense of helping him out of the saṁsāric shackles!
The task is also effortless as it were at the same time for Naṭarāja, as there is a certain match between the two participants here: the length of the pāda of Naṭarāja exactly matches the length of the spine of Apasmāra! No conscious and effortful endeavour is required on the part of the Lord in order to effect this ; for it happens ever so naturally! It is as a conspicuous consequence of this act that even Apasmāra is able to raise his head (literally too), and it also explains why Apasmāra is trying to catch a glimpse of the face of Śiva, and why there is a smile - a contagious one, so to say, howsoever mild or faint - on the face of Apasmāra attempting to emulate that of Śiva.