Click and drag the handles to resize the icon. To cancel the stretch, press the Escape key. To remove the stretching handles, click away from the icon. You can preview many files in the Nautilus window just by looking at their icons in the main panel - you don't need to open the files. If you enlarge a text file's icon by zooming or stretching, you can see more of the text.
Music plays as long as the pointer is over a music file's icon.
You can use the Nautilus window to look at a file's contents without opening it for editing in an application. Using a viewer instead of opening an application can save time and memory. Most text files automatically appear in the Nautilus window when you double-click their icons. However, some files open automatically in their applications. For such files, right-click the icon and choose Open With.