How to add Adding Photo Overlays in the Google earth map

Adding PhotoOverlays

Earlier releases of KML allow you to include small photographs in description balloons attached to placemarks in Google Earth. Entire layers, such as Panoramio, consist of user-contributed geolocated photos. To view these photos, the user must click the placemark icon (or click the name in the List panel) to open the balloon containing the photo.

PhotoOverlays are photographs that are directly embedded in the Earth's landscape. They can be 2D rectangles, adding scenic "billboards" that expand the base aerial imagery of the Earth. PhotoOverlays can also be projected onto cylinders or spheres to create virtual panoramas that the user can "enter," explore, and inspect in detail. In addition, KML 2.2 accommodates very large PhotoOverlays, containing many megapixels of data . These images require you, as KML author, to provide a set of downsampled versions of the image so that Google Earth can efficiently load only the portion of the image that fits into the current view, and at the appropriate level of detail.

In addition to this page, be sure to read the "Topics in KML" page on Cameras, which are used by the PhotoOverlay object. If you are using a very large image for the PhotoOverlay, you will also need to create an... 

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sources:https://developers.google.com/kml/documentation/photos