Thank you for using product our,
No portfolio don't config that select number column. but You can set with for image and can set 4columns.
I saw, you have custom css with for each item:25%. This here:
width: 25% !important;
But item have border , margin,...of image. contaner of 4 image will larger 100% => it will has not enough fill space for 4 image.You can set it that is 20% or 22%.
I will check it for you.