As I said before, I run this website all by myself. Every time I have a new design, I need to put it online as easy as possible. So I do not organize fashion shoots with these designs. My print-on-demand provider offers me an option to create mockups. They have put a lot of work and effort into the creation of the mockups so they are as realistic as possible. But there are a lot of factors that can change our perception of color. So the color, size or position may be a little different when it arrives. Even the garment can be a little different in the mockups I use on the front page because they are rendered using a mockup service and do not come from my print-on-demand provider. The first packshot you see when you click on a product is the most realistic image.
Just know that I will always do my best to provide the best quality mockups I can!