Taylor's wording was precise, but he did not specifically identify the object. In High Cliff, Coast of Maine there are many "in addition to" objects. I think he was referring to this lady profile, because he used the word "poise" and because it is the least "iffy" of all "in addition to" objects I see.
In the context of this painting, the lady profile is actually a rock formation. That is what the thing actually is. What Homer also saw and embodied into the painting, "instead of" or "in addition to" the rock, is this woman, a thing the rock formation actually is not, which represents, not a physical object, but a spiritual or poetic object. Although that object only existed in Homer's mind until he expressed it by embodying it in this painting, he probably saw the suggestion of that image in the actual rocks.
Here the real and the ideal are very well balanced. It is not at all obvious until you happen to see it, but once you do see it, there is little doubt. As Taylor wrote, "...this seemingly unconstructed but undeniable poise..."
