1. A printing apparatus for printing an image on a recording medium after applying a predetermined finish processing to the image, the apparatus comprising: a document reading part configured to read a document to create the image to be printed; a reception part configured to receive a creation request of a preview image reflecting the predetermined finish processing being applied to the image; a preview image creation part configured to create the preview image based on the image created by said document reading part in response to the creation request; a display part configured to display the preview image created by the preview image creation part; and a print part configured to print the preview image reflecting the predetermined finish processing displayed on the display part, wherein upon reception, at the reception part, of an initial orientation designation of an initial orientation of the document read by the document reading part, when a first relationship between the initial orientation of the document and the image on the document is different from a second relationship between an output orientation of the document and the image on the document, the preview image creation part adjusts the preview image by adjusting a position at which the predetermined processing is applied to a position corresponding to the initial orientation of the document indicated in the initial orientation designation, which is a position corresponding to the first relationship.