Mermish Essence

In the Flight of the Prince chapter of book 6, Snape is able to block Harry's spells, including the Cruciatus Curse, which Harry casts several times against Snape. According to canon, the Unforgivables cannot be blocked. I know that one can resist (Imperius Curse) or endure (Cruciatus Curse) but not block them. So, how was Snape able to do so?

That is, if it wasn't revealed to you in the first place. We see only a few instances of prophesying throughout the books, notably, when Trelawney prophesied to Dumbledore about Harry and Voldemort, and to Harry about Wormtail rejoining Voldemort. (Side note, is it just me or does Trelawney have a thing for Voldemort?) We know that when the crystal sphere housing the prophecy smashes, the prophecy is retold.

It looked out of place My guess is that it simply looked out of place, either because it didn't match the rest of the decor (it was patterned on Slughorn's pyjamas, hardly the most common material used for an armchair), because he'd neglected to cover himself in the same dragonsblood spatter or was just too clean in general. Cushions lay deflated, feathers oozing from slashes in their sides; fragments of glass and china lay like powder over everything.