You can get the most up-to-date thumbnails in the Thumbnails view. As you draw, a series of small images (thumbnails) is generated. These thumbnails are automatically refreshed based on the refresh duration you set in the Preferences dialog box (Advanced tab, Delay Before Updating Thumbnails parameter).
You can choose update thumbnails immediately. This deletes all cached thumbnails in the Thumbnails and Timeline views, and forces new thumbnails to be regenerated.