This part is a mold of the inner cavity for a dishwasher's tower protector. https://www.appliancepartspros.com/whirlpool-protector-tower-wp8268825-ap6012262.html
You can use this design to make your own piece from or simply as a way to protect this piece if it's in storage.
Other part info:
| BLU | 3368995 |
| WHT | 3369761 |
| IGD | 8268825 |
The author marked this model as their own original creation.