tile grout color adjustment?

[Gawdzira]

I thought I had an answer for this (in the Symbols forum page) but now I have a question. I wanted to show an example of changing the grout color on the existing file. Here are the steps to do that in pics but basically

1. I did a back up entire plan for the plan file which is an easy way to get the image file for your tile.

2. I edited that in Photoshop for a darker grout color and saved the image as a .png

3. when I brought that back in I needed to rescale the image in order for it to align with the old image

 

This seems odd to me. If I took the exact image from the material file, why did it come back in at a different scale. The original file had it at 8" x 7" but I needed to both resize and offset. The image files loaded in backwards so read them in named numerical order (from the bottom up on my screen).