Differentiating sensation is always what's happening.

'Form', or differentiated sensation, is an ornamentation or decoration of 'Emptiness', or undifferentiated sensation, as it embellishes it.

‘Form’ is the moment-to-moment creative act of differentiating sensation at the millisecond timespan: the predominantly pre-conscious emphasizing, de-emphasizing, and 'turning off' of the infinitesimal pixels within the undifferentiated field of sensation to create differentiation.

The ornamentation of form appears as a continual play of particular differentiation, always fresh, always unique, never repeated.

Hence traditional phrases such as "All of one’s vision is said to be ‘as an ornament’." or "Freely Resting in Appearances." (Nangwa Chogshag)