If you have not already installed the Sibelius Scorch plugin, a dialogue box will pop up asking whether you want to install it. To view the sample sheet music, click 'Yes' on the dialogue box after reading the information. The plugin will then install itself and the sheet music sample should appear.
If you are unable to see any music on the left-hand side of this page, you will need to install the Sibelius Scorch plugin.
This is a free download that allows you to view sample sheet music from within your browser.