BfA Prot: Holy Shield

[Shinela]

So I'm probably missing a big thing here, so please do help me up! Anyway:

Holy Shield allows you to Block a magic attack.
Block now reads: "Blocking adds X armour against an attack."
Armour reads: "Physical Damage Reduction: X"

So how does blocking a spell help exactly now?

[Nadiru]

So I'm probably missing a big thing here, so please do help me up! Anyway:

Holy Shield allows you to Block a magic attack.
Block now reads: "Blocking adds X armour against an attack."
Armour reads: "Physical Damage Reduction: X"

So how does blocking a spell help exactly now?

Sounds to me like it applies block as if the next spell were not a spell.