The way I would do it is,

Create a large picture of the hat, make it a pdf file, i.e.,  hat.pdf

Upload it to you website, preferably into a newly created folder, i.e.,
downloads

On the webpage Insert a small picture of the hat, i.e., hat.gif

Then click on the hat.gif image, select Insert, Hyperlink and fill the box
with\

/downloads/hat.pdf

Upload the web files and then visit your site, double click on the hat image
and up comes a pdf file of the hat which then can bee magnified to the size
of choice.