Comments on William Wordsworth’s much-debated poem “A slumber did my spirit seal” (1800) fall into two interpretive positions: “shock” readings and “non-shock” readings. The poem can be understood in a new way through the concept of intermedial experience and the rhetorical device of ekphrasis. I call for a kind of visual reading that does not let the intermedial experience of poetry be reduced to an interpretive position, as there always remains an excess of experience, something that is not part of the interpretation and cannot be exhausted by offering another interpretation. Becoming involved with the excess and reflecting on it can yield insight into how intermedial experience is constituted. In the readings of “Slumber,” it has consistently been the empty space between the poem’s two stanzas that has appeared to generate such excess. I discuss the images readers have seen in reading the poem, the narrative they have used to describe them in their own words, as well as the effect of the empty space on their responses. Who is the source of the significance of the poem’s visual images, the reader, the poetic I, or Wordsworth himself, and what does the reading come to in terms of the selves involved? I argue that interpretive positions such as the “shock” and “non-shock” readings of “Slumber” can be viewed as ekphrases in which the reader verbally describes the images of the poem with the consequence of narrative appropriation. In doing so, the intermedial experience of poetry is reduced to an interpretive position, and the reading process subjectively closed off into a private sphere. Studying the device of ekphrasis shows how reading, understood as intermedial experience affected by empty space in “Slumber,” both maintains and disrupts this sense of subjective closure.