It’s surprisingly common to find images on websites these days that has not been resized properly.
You want your website to load as quickly as possible to make for a pleasant user experience.
If you intend to show an image at 200x200 pixels, make sure you resize the physical dimensions of the image instead of just leaving it to html/css.
There are a few exceptions for this, where javascript is used to show a larger version, but other than that, treat your users right, don’t make them wait longer for no benefits.
