In the context of practicing Eiriu Eolas, it is an earnest focus on the meditation/prayer and its meaning. Where, for a time, my aim is to think more or less solely on my intention to connect to it (or get back to it if my thoughts should stray) and to be aware of myself and as I do. So it is also quite simply a practice of mental discipline. Visually, I sometimes imagine the awesome vastness of the universe. I also see snapshots or images (some metaphoric, some literal) of what's contained in the prose of the meditation.
Since the mediation occurs after rigorous and varied types of breathing (which are designed to help detoxify ourselves from stress among other things), the meditation is a means towards connecting to, and being receptive of, the 'higher' - after "my cup" has been drained a bit further of the 'lower'. To use another analogy, it may be likened to a deep cleaning of a house that is infested with dust mites, mold and dirt and then, after a deep cleaning, replacing things with new and beautiful hypoallergenic furnishings.