Update: kaylamour had the answer: This is a trick to merge calendars in iCal — Pick a calendar from the list in iCal, then export it to the desktop. Now drag the exported calendar.
It's Mareen Fischinger, a photographer in Düsseldorf, Germany. This blog shows some of her personal life, behind the scenes and ideas, too — in no specific order.
Her hobbies are understanding systems and solving problems. She is a perfectionist and hyperactive at times.