hello there,
well these styles are used to set the images in the photo album section.
As Imar has used the two themes in his project, one of them are 600px wide.
So to set the images for the photo album section these styles are being used, which sets the image height and width forcefully to be 280 px and 200 px respectively. Further for the width there is padding of 10 px at top and bottom, 20 px on the right side and finally no padding for left side.
Code:
.itemContainer li img
{
width: 180px;
margin: 10px 20px 10px 0;
}
This style sheet is dedicated to images only. That you will find in chapter 13 and moreover you can have better understanding on page no. 459.
Hope this helps.
Cheers,
jack