Hello Denis,
This looks like a patch found on the web. See for instance :
extensions.joomla.org/extensions/mobile/apple-display/5862 and this is a core modification.
Back to the initial code, the website displayed with a strange template, no custom.css for instance. I've changed the settings in sh404sef and set the tabless option to "no", because my template is tabless.
Now, my template is ok and futhermore I can load the Iphone template!
I have to investigate further how to use the component in order to display menu and so on.
That's a good job Denis! Thank you very much! How can I thank you?