You can always change the order of the pictures on your profile after you have uploaded them. This simply works by drag and dropping the pictures manually in the right order.
Click on the blue edit button on the top right to open the image settings of your profile.
Click onto the picture you would like to move and hold. Without clicking again you can now move the picture to a different position before letting go of the mouse.
You can change the order of one picture as well as rearrange the order of all your pictures, if you want to.
Tip: Always start with the most powerful images that have a strong focus on the product itself.