This image has not been edited from the default upload options in post editor:

It's too wide for the container, but the container will squish it. It should look distorted even on a large sized screen, and will be hard to recognize on a mobile screen.

Code if needed (the code tag in Known's Rich Text Editor doesn't seem to be cooperating for me at the moment): https://gist.github.com/drkokandy/a1a421fd6c8e3aebcf18

The image again, with img-responsive and no size info:

This image is properly responsive. This adapts to the size of the container it is within on both mobile and desktop screens. It's powered by predefined bootstrap style "img-responsive".

Code, if needed: https://gist.github.com/drkokandy/b6185b7af90e535c2eb1

Here's the image again, with img-responsive but no change to default width and height:

It doesn't seem to matter if width and height are defined. This adapts to the size of the container it is within on both mobile and desktop screens.

Code, if needed: https://gist.github.com/drkokandy/eaa0ad6091f3d45d19b5