Additional Images Size too small

Hello,

I'd like some help with increasing the size of the additional images for products please.
Currently it's very small - see attached screenshot.

In the backend, I tried to play with the image size but they don't seem to increase the size on front end.

My website is www.tyreworld.co.nz/cars/toyota-corolla

Dear Alvis,

Seem there is something wrong in the configuration. Please submit a new ticket to EShop category to send me the your site information so I can go there to check for you.

Hope to receive ticket from you soon.

Sincerely, Giang