With some PHP Contact Management Systems (CMS) there is the facility to process images. It would appear that your CMS is doing this by displaying the small 74x109 pixel preview of the main image which is 1200x1600 pixels.

You need to investigate the capabilities of your CMS by downloading user manuals etc and joining a Forum or discussion group that has been set-up specifically for your CMS.

I have never been involved in a site that uses this image resizing via PHP CMS, so that is now the end of my useful contribution.
Search on Google for a users forum I'm sure you will manage from there.

PS
Don't make all your images into jpegs, some images (Logos etc) are better kept to gif format.

PPS
Download a trial of Macromedia Fireworks which is the best program for "Processing" images for web pages. before the trial runs out, It will show you how to handle and efficiently optimise different images for web publication.