You can, you'll have to edit the galleries/grid_lightbox/css/common.css file. Adjust some css in the .pg-gl class to have a width of 1001px and a left padding of 2px. Here's the full css you would change:
.pg-gl {
background-color: #1E1E1E;
font-family: Arial,Helvetica,sans-serif;
padding: 8px 0 8px 2px;
width: 1001px;
}
Also, all those dogs are pretty awesome.
-justin