This Seeking Tech article compares Final Fantasy X/X-2 HD Remaster with the PS4 Image Enhancement feature of the PS5 Pro enabled and disabled. Both of these originally run at 1080p.
You can check out the videos below:
Final Fantasy X HD Remaster:
Final Fantasy X-2 HD Remaster:
As you may be able to tell, the polygonal textures appear sharper with the PS4 Image Enhancement setting enabled.
The computer-generated cut scenes and background does not appear any sharper with this feature turned on.