In Portrait mode, all the fields in the header and child are always displayed in a single column irrespective of the layout defined in the SFM process.

In landscape mode, all the fields of the header records including the long text area field are displayed in one column or two columns as per the configuration in the SFM page layout. Whereas, all the fields (except long text area field and field with more than 40 characters) of the child records are always displayed in two columns.