As a philosopher, you define constraints for any good theory explaining what you are interested in, then you go out and search for help in other disciplines.

As a first-order approximation, I would say that phenomenality is "availability for introspective attention": Consciousness is a property of all those mental contents to which you can in principle direct your attention.

For a human being, to possess a consciously experienced first-person perspective means to have acquired a very specific functional profile and distinctive level of representational content in one's currently active phenomenal self-model: It has, episodically, become a dynamic inner model of a knowing self.

As modern-day neuroscience tells us, we are never in touch with the present, because neural information-processing itself takes time. Signals take time to travel from your sensory organs along the multiple neuronal pathways in your body to your brain, and they take time to be processed and transformed into objects, scenes, and complex situations. So, strictly speaking, what you are experiencing as the present moment is actually the past.

Subjective time flows forward, the phenomenal self is embedded into this flow, an inner history unfolds. That it is why it is not a bubble, but a tunnel: There is movement in time.

The Ego is a transparent mental image: You, the physical person as a whole, look right through it. You do not see it. But you see with it.

If we lose the ability in question for a single moment only, we are immediately being hijacked by an aggressive little "Think me!" and our mind begins to wander.