Andere Version verwenden
Scheint nach wie vor die einzige Möglichkeit zu sein. Also entweder Windows-Version oder ältere Mac-Version einsetzen.
S.a.:
http://answers.microsoft.com/de-de/office/forum/office_365hp-excel/bild-einfügen-in-excel-kopfzeile-ms-office/f5de5d4f-a8d2-498b-80af-9b7e39145309?tab=question&status=AllReplies&page=1
http://answers.microsoft.com/en-us/search/search?SearchTerm=header+picture&IsSuggestedTerm=true&tab=&CurrentScope.ForumName=mac&CurrentScope.Filter=macoffice2016-macexcel&ContentTypeScope=#/mac/macoffice2016-macexcel//1
S.a.:
http://answers.microsoft.com/de-de/office/forum/office_365hp-excel/bild-einfügen-in-excel-kopfzeile-ms-office/f5de5d4f-a8d2-498b-80af-9b7e39145309?tab=question&status=AllReplies&page=1
http://answers.microsoft.com/en-us/search/search?SearchTerm=header+picture&IsSuggestedTerm=true&tab=&CurrentScope.ForumName=mac&CurrentScope.Filter=macoffice2016-macexcel&ContentTypeScope=#/mac/macoffice2016-macexcel//1