Part of the design of a web site/application includes the photos or images that you wish to use.   These are not random.  Instead, they are planned up front.  The selection of the pictures begins with a discussion about your goals.   From your goals comes the plan for a photo shoot.

Photo shoots are time consuming.   First there is the content to obtain.   The content includes the mood and feelings the photo shoot needs to capture.   Once the photos have been acquired, they are presented to you for inclusion in your web application/site.  These images then go to the digital dark room for editing.  Afterwards, the images are added to your web application.

At a minimum, you should expect to pay for at least four hours of time.