This consciousness turns back; it doesn't go further than name-and-form
In his analysis, Buddha sought to identify the semiotic precursor/counterpart for the experience of death. Going backwards from death, he identified the notion of "life" (jati, the notion of separate organism that gets born and dies) as the precursor/counterpart of death.

Going further backwards, he identified a chain of precursors/counterparts supporting each other in the process of semiotic development. These were appropriating experience aka becoming, object grasping aka goal-setting, obsession aka craving, associating a feeling with object, contact with object, six doors of contact, and namarupa or the labeled objects themselves.

He then tried to identify a precursor or counterpart for namarupa, information about objects and identities. He realized that vijnana or ability to differentiate objects from their background and from each other (the function that gives rise to our basic awareness of the world), is the precursor/counterpart of namarupa.

Naturally, the next step was to try and identify the precursor/counterpart for vijnana (recognition/differentiation). Upon much thinking, Buddha came to conclusion that namarupa itself was the counterpart of vijnana. Indeed, there may be no differentiation of objects without capacity for recognition, and there is no capacity for recognition without notions of objects.

At that moment Buddha realized that the entire chain of phenomena he has been analyzing, including death, is completely included in the realm of objective thinking. In other words, the entire experience of living and dying is a story our object-obsessed mind is telling itself. This realization was a huge breakthrough and a major step in the direction of Enlightenment.

At a later date, Buddha reconsidered this idea that vijnana and namarupa are each other's precursors and instead came up with an alternative chain which had "accumulated tendencies" (samskaras) and "ignorance" as two more links of the chain. This is the version of DO that ended up becoming the classic we know today.

Anyway, the importance of this realization still stands, that all our experienced phenomena are mind-made ("form is emptiness"), and this mind itself is a reflection of interaction of phenomena since beginningless times. In Mahayana we say, phenomena are empty, and mind is empty as well, these two emptinesses are a reflection of each other and yet they manifest as seeming reality ("emptiness is form"). This relationship is an important topic of analytical meditation in Tibetan Mahayana.