Preview of screenshot in unity

Instead of holding the game, you can load your screenshot into a texture and show it to the user. Use the WWW class. (Resource-wise, if thats critical in your application, you shouldn't use Application.CaptureScreenshot if you want to show the image afterwards, but use something like this where you already have the data and don't need to load it again).

 IEnumerator TakeScreenshotAndLoadItIntoTexture(string filename) {
   Application.CaptureScreenshot(filename);
 
   WWW www = new WWW("file://" + filename);
   while(!www.isDone)
     yield return null;
 
   myPreviewObject.renderer.material.mainTexture = www.texture;
 }