Looks pretty good. The bold vs. regular treatments in the text create interest in both the visual sense and in meaning. Both the text and the images seem to be in the foreground considering that both will move depending on the size of the viewport. Perhaps you could try some graphic blocks of color or lines in the background that stay static behind the text and images to create more depth and interest in the negative spaces. The graphics could also be different per postcard, indicating the different personalities of the people speaking.