What are the Layer Output Scale and Map Output Scale properties used for?
Both of the output scale properties are used to set the scale of the map before the content is exported to an image. If the scale specified results in one or more layers not being displayed due to that layer being outside its scale-dependent rendering threshold, those layers will not be included in the exported KML image. If the layer or map being exported is all vector layers, only the scale-dependent visibility of the layer is checked. If none of the layers are using scale-dependent rendering, the Map Output Scale property is not used at all.
