There are 4 endings for this game.
1. Love Ending.
2. Kink Ending.
3. Bad Ending.
4. Casual Ending.
I can not remember where the 2 missing images you don't have are found.
However you have not played the Bad Ending and the Casual Endings.
If you complete those endings in the guide, I am certain you will be acquired them and your image gallery will be completed.
Here is the guide to achieving all the endings:
https://hashiespicy.itch.io/beddingtheboss/devlog/937680/thanks-for-1000-downloa...