question about resize in photoshop

Hello,

I am working between Acrobat Pro and Photoshop.

In Acrobat Pro, in Edit mode, I select the page and right click "modify with Photoshop."

So it opens Photoshop and I see this page. So I resize it in Photoshop :

In Photoshop I save. So the resized PDF  is saved in the original PDF.

But when I go back in the PDF file I have this result : you can see that it does not corresponds, and around the resize part you can see that the blue outline around the resized part is away from the page. Why ?