This is a work in progress only detailing each Holofoil pattern's role during Generation VI. Nothing is currently listed from the Black & White Series and before.
Sheen Holofoil is the default Holofoil of the XY Series, replacing the Black & White Series Tinsel Holofoil. Sheen Holofoil refracts in a similar way as Mirror Holofoil, but in a diagonal direction instead of vertically up and down. The Japanese Holofoil starts from the bottom-left of the card and transcends to the top-right, while the Holofoil of the English and other international languages travels in the opposite direction: from bottom-right to top-left. It is currently unknown if the Korean Card Game will adopt this Holofoil Pattern, as Collection X • Collection Y isn't even announced for release as of February 16, 2014, but if the BW Series is any precedence, the Korean cards will continue to utilize Cosmos Holofoil.
Cosmos Holofoil, although the standard Holofoil for most of the duration of the Pokémon Trading Card Game, takes on the same role during the XY Series as it did during the Black & White Series—as a purely promotional Holofoil. Not currently printed for the Japanese XY Era, Cosmos Holofoil has only been used for the English XY Series.
Starting as a Holofoil Pattern exclusive to Ultra Rares, Cracked Ice Holofoil, much like Cosmos Holofoil, became exclusively a Promotional Holofoil. Although no cards released during the Japanese XY Era have currently utilized, the English release of the XY Theme Decks—Resilient Life and Destruction Rush—released their featured cards as exclusive Cracked Ice Holofoils. This Holofoil is often described as Broken Glass or Shards as it reflects as many triangle pieces.