Why does the Extended function of Photoshop and Illustration in Mac differ?
In Photoshop, press option and Roll the mouse Wheel button -> reduce the image.
In illustration, click on option and roll the mouse Wheel button -> Expansion the image.
Why is it different? And how do you fix it?
I perceive no difference.
alt-wheel up reduces, alt-wheel down increases the display for me in both Photoshop and Illustrator.
I work on Mac (10.12.6), too, and I do not perceive that difference so there may be something else.