Click component parameter button and scroll down modal window to Instant preview settings. You can configure instant preview of template by using following settings.
Mouse event which, if triggered, closes instant preview window. Mouse Out and Mouse Click are possible. On Mouse Out preview window closes when mouse cursor leaves thumbnail area. If Mouse Click was chosen then user has to click to each preview to close it. This approach has some advantages though. Since instant preview was opened on Mouse Over event, and left opened, then user can pop-up more than 1 preview at 1 page.
Change instant preview box and/or image width. You may increase or decrease values to output template preview of size you need for your store.
Value for image box padding if needed
Choose type of effect here.
Effect length is length of effect in milliseconds (1/1000), so 350 milliseconds are 0,35 secs.