From the interview with the US filmmaker Bruce Branit who created this film:
What triggered the desire to include the woman within the story?
I think it came from hearing a story about the Taj Mahal. (Taj Mahal was the working title while we were filming it) It was just a monument to a woman who was sick or dead and that tied in well to what I was already thinking about this man building a world. It provided the emotional "why" to the story.
Why does the world builder hide from her?
That's somewhat up to interpretation. He is essentially creating a dream or a memory for her in hopes of waking her. The photo's at the beginning are supposed to represent a full life these two have experienced, so he draws from these to build a new world every day for her. But seeing him in his digital form (originally he would have looked monotone or like a Star Wars hologram) would likely ruin the emotions he is hoping to stir, and confuse her.