Is the Ocean Samadhi a metaphor or an actual meditation?

In Huayen related documents I see the phrase "ocean samadhi" a lot. (also ocean mirror samadhi, ocea seal samadhi) Here is one source: > Huayan teaching features a range of holographic samadhi instructions > drawn from the Flower Ornament Sutra. These practices help clear away > limited preconceptions, foster fresh perspectives on reality, and > expand mental capacities by expressing our deep interconnectedness. > > ... Another model is the > "ocean mirror" or "ocean seal" samadhi. In this image, awareness is > like the vast ocean surface, reflecting and confirming in detail all > phenomena of the entire universe. Waves of phenomena may arise on the > surface of the ocean, distorting its ability to mirror plainly. But > when the waves subside as the water calms and clears, the ocean mirror > again reflects all clearly. Our individual minds are like this, often > disturbed by turbulence, but also capable of settling serenely to > reflect clear awareness. > > Ref . I searched Cleary's Avatamasaka translation and only found the word Ocean used as a metaphor or simile. (The kindle stops searching at 500 hits, well before the end of the book) Anyhow, can't tell if this is a sort of visualization exercise, literally involving thinking about waves and the ocean, or if this is just a metaphor for the meditative states achieved in samyak-sam-bodhi.