Both galleries have dimensions of 100% x 100%.

simpleviewer.load('sv-container', '100%', '100%', 'transparent', true);

Your first gallery is on a page of its own and therefore takes up 100% x 100% of the user's browser window.
The second gallery is embedded in a container (alongside other content on the page) and so fills the container 100% (in both width and height). (The container div has a height of 700px and the gallery has a height of 100% so the gallery's actual height is 100% of 700px which is 700px.)
If you wanted the gallery to be the same size on both pages, you could set the gallery's dimensions to be fixed pixel values instead of percentages, e.g.:

simpleviewer.load('sv-container', '1024', '700', 'transparent', true);