The speaker finds three small frames of 8mm film in his bed and recognizes a past lover in them: she wears a long white dress, her hair lit by evening sun, playing with dogs. The image is ordinary and tender, and it has clearly stayed with him.
He keeps the discovery from his wife, and the poem hints at why. She hasn't lived through what he shared with this earlier woman, a love affair tied up with film-making. The speaker lists the leftovers of that time: cut frames, peeled splicing tape, curls of white leader clinging to skin. The film scraps blur into her body, which seems to have been everywhere, in the work and in the bedroom.
The mood is quiet, secretive and a little wistful. The short last lines, "Everywhere. Until now," suggest that the traces once surrounded him and are now almost gone, so these three frames feel precious, and slightly guilty to hold.