User/browser to change thumbnail size

I want my user to be able to change the size of a list of thumbnails.

There will be 3 links, Small, Medium and Large selecting one of them will update the page using the selected image size.

My current idea was to use the URL to pass the “variables”

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Any ideas why the above doesn’t work, sorry my php skills are very very limited but I’ve used the above idea before and its worked, im using cagegory.php I want to avoid making to many templates due to the product range im going to have.

https://www.wrapsodyscarves.com.php5-18.websitetestlink.com/category/cashmere/#?grid=small