Cosmetics in NieR Replicant ver1.2247... are extra features that change the visual model of NPCs, loading screens, and projectile animations of the game. Nier Replicant Coscmetics can only be acquired by downloading and playing the DLC - World of Recycled Vessel. This page includes a list of all the Cosmetics with their specific descriptions.
Cosmetics - Nier Replicant ver 1.2247
Cosmetics in NieR Replicant ver1.2247... are exclusively limited to: NPC costumes, loading buddies, and Enemies' bullets. All three are unlocked by completing different challenge levels of the DLC World of Recycled Vessel content.
While costumes are skins that change the the outfit of an NPC, Enemies' bullets are the models of Enemies' ranged Attacks, and loading buddies are different NPC animations that appear while the game is loading.
Cosmetics - NPC Costumes
After each costume set is unlocked, you can apply them in the options menu and then start a new game. Once applied, all the respective NPCs - namely, Nier, Emil, and Kaine, will be wearing the new costume at all times, except during some CGI cut scenes.
There are two costume sets available in Nier Replicant ver1.2247... DLC World of Recycled Vessel - The Kabuki Costume Set and the Samurai Costume Set. While the Kabuki Costume Set is acquired in door one of the DLC challenge levels, the Samurai Costume Set is acquired in door two.
Cosmetics - Loading Buddies
As each costume set is acquired, they are rewarded along with a respective new loading screen. These loading screens replace the original one featuring Yonah with Kaine and Emil instead, both in their new costumes.
Cosmetics - Enemies' Bullets
In addition to new loading buddies, unlocking and applying either costume set to the game will also change all orbs projected by Enemies into Emil's heads.