![animal_ears bear no_humans no_pants photoshop_(medium) pooh puma_ag pun sakkan shirt smile solo stuffed_animal stuffed_toy t-shirt tail winnie_the_pooh rating:s score:8 post #1372700](/cdn_image/preview/e0/a2/e0a2657a4dddde1415ee98cfec8424f4.jpg)
Contrary to the what tag, Posts that you do not understand at all and leave you thinking, "WHY would you do that?"
Less that they leave you in confusion more that you just do not understand why they would do it. Similar to unlikely crossovers; you can see that they did it so it would not categorize as 'what', but would still qualify as "Why?".
Its pixiv equivalent are どうしてこうなった OR どうしてそうなった.