What you show in the first screenshot involves image display in item listings (=category view).

To NOT show the item image on the actual "item view", you need to disable the relevant option under the "Item view options" in your category settings.

There is no inheritance between the parameters in the 3rd tab of the category edit form.

Plus, most of the times you need this kind of granular control for what is shown or not in category listings and item views.

If you're coming from Joomla articles, you'll notice that K2 options are more consistent and simply make sense.