What you do practically is to name all aspects of the jīva as brahman. My body, my hand is seen as Brahman, my body, my mind, everything that I used to call "I" is seen by Me as Brahman. My life, my environment, the others around me etc.

This is how you shift your identity from little me to 'just me'. Thus ahaṅkāra and brahman are equated. Only this will not happen overnight.

Because every meditation is an activity, at this level you are still a doer, an ego, ahaṅkāra.
In this sādhana (practice), ahaṅkāra, ego, has probably not yet been properly ignored. So it is not a real nididhyāsana (contemplation).

In nididhyāsana the contrast between meditating (doer) and meditating (done) is nullified. So knowing that I am a Brahman, the only thing that is, is different from seeing the person as a Brahman.