Across the tabletop

At the end of my first afternoon in the restoration room, I stepped back from the tabletop. Beneath the broad ceiling lights, the polish looked unbroken, and I told the conservator that no further work was needed. She said nothing, but placed a small lamp almost level with the wood. As she moved its beam slowly, a chain of shallow scratches flashed along the centre and a cloudy patch appeared near the far corner. The table had not changed, yet my certainty had.

Select two words or phrases from the passage that reveal why the narrator's first assessment of the tabletop is unreliable. Explain what each selection shows.