The rock, whose upper surface measures roughly 1.5 metres along its long axis, is inscribed with cup-and-ring motifs, a form of prehistoric rock art found widely across Atlantic Europe and consisting of a shallow circular depression, the cup, surrounded by one or more carved rings. The most legible example here is about 16 centimetres across, with a central cupmark enclosed by two rings that open at the south-west, and a narrow radial groove running outward from the cup through those rings down towards ground level. Beside it, a second motif carries its own cupmark and radial groove, this one oriented northward, and the two are joined by a curvilinear feature. Further picking continues west along the south-west facing side of the rock, though much of it is now difficult to read clearly.

What makes the Kealduff panel quietly unusual is not just the carvings themselves but their setting within a small cluster of marked stones. Some 20 metres to the north-north-east, a second boulder, also partly swallowed by bog, carries its own cupmarks. Another 40 metres beyond that, a further portion of rock protrudes from the peat bearing a picked line and additional picking. The carved rock also lies just east of a sub-circular walled enclosure roughly 70 metres in diameter, a feature that does not appear on any historic maps, suggesting it had already faded from memory or practical use by the time detailed surveying began. Whether the enclosure and the rock art are related, or simply neighbours across a long stretch of time, is not known. Cup-and-ring art is generally associated with the Neolithic and Bronze Age periods, but its precise function remains genuinely unresolved, with interpretations ranging from territorial markers to ritual or cosmological significance.