8 Snow layers will give 1 snowball when mined with a shovel with or without silk touch.

1 snow block when mined with a shovel gives 2 snowballs (1 snow block when mined with silk touch)
8 snow layers when mined with a shovel gives 1 snowball whether the shovel has silk touch or not.

Not much of an issue, just seems like unexpected game play as 8 snow layers is the same as one snow block.