Ok! I remember this now and it's very obscure. For my menu on iphone, in order to display a logo image, I had to go to first menu item (in my case HOME) and add in Parameters (Basic) menu image and select an image. I did this on the first menu item and it gives appearance when displayed on iPhone as a header logo (but in reality it is a menu item image for first item).
If the developer of this tool recommends another method, please advise.