why the result is different when using source images with varying source size

<img width="1553" height="742" alt="Image" src="https://github.com/user-attachments/assets/20337831-1439-4fc4-a029-391895a1dc09" />

<img width="1541" height="733" alt="Image" src="https://github.com/user-attachments/assets/9f9f2968-c5fa-48aa-a548-6415f8a70223" />

I use two different size source images, but using big one it fails.