Product photos lose quality

Hi guys,

Having a little problem with the product photos.
Basically – once I upload a photo to the product – the quality decreases dramatically. You can see it in featured products as well as on the category page.
I used a few different sizing. On the screenshot, Limoncello is 300×400 pixels 300 dpi
Theratonic is 800×1067 72dpi – just like the other photos that were provided with the template of the products.
Both of them seemed to be zoomed in and with quality significantly lower.
The moment that I switch to another theme – let’s say twenty twenty-one – photos look normal.

Thanks in advance!

The page I need help with: [log in to see the link]