You can save a thumbnail image or an image sequence (playblast) with your scene file when saving or exporting it (Choose Content Browser. A scene file's playblast runs when you move the mouse over its thumbnail in the Content Browser.
> , , , , or ). This makes it easy to identify a file in theThumbnails and playblasts are available only for Maya ASCII (.ma), binary (.mb), and FBX files. Thumbnail images are saved with a 256 x 256 resolution in .ma.swatch, .mb.swatch, or .fbx.swatch files in a mayaSwatches folder in your project where you have saved the scene file (such as the project's \scenes folder). Playblasts are saved in .ma.preview, .mb.preview, or .fbx.preview files, with one file per frame captured.
Watch the video below for information on how to create a thumbnail or a playblast for a scene file. See Capture Thumbnail/Playblast for details on the options.