If you are showing images of different sizes a space has to be reserved for the largest image width and largest image height plus any text otherwise the rest of the content in your page will move every time a different sized image is shown. In order to reserved the space required a focal div is dynamically sized to the largest width and height, the images are then centered within this div.
The images text is contained in a seperate div and shown below its image, the text remains at the bottom of the focal div irrespective of the size of its image.
You can adjust the display size of the images by changing the value of variable imageSize this number relates to a percentage so if you set it at 50 your images will be displayed at 50% of their respective default sizes.
You can also set a fixed width and height by setting variable imageSize to zero and using the variables fixedWidth and fixedHeight.
In both cases the overall size of the display will adjust accordingly to the largest width and largest height.
You can change the color and the size of the border around the image with variables displayBorderWidth and displayBorderColor
The text and its box can be customised by using the text_div css rule