Over the past decade, multi-touch surfaces have become commonplace, with many researchers and practitioners describing the benefits of their natural, physical-like interactions. We present a pair of studies that empirically investigates the psychophysical effects of direct interaction with both physical and virtual artefacts. We use the phenomenon of Kinesthetic Figural After Effects-a change in understanding of the physical size of an object after a period of exposure to an object of different size. Our studies show that, while this effect is robustly reproducible when using physical artefacts, this same effect does not manifest when manipulating virtual artefacts on a direct, multi-touch tabletop display. We contribute quantitative evidence suggesting a psychophysical difference in our response to physical vs. virtual objects, and discuss future research directions to explore measurable phenomena to evaluate the presence of physical-like changes from virtual on-screen objects.