In order to have responsive site, you will have to make large images responsive for different screen sizes
1. Double click on image.
2. Check the Weight optimization box, this option will automatically generate image for all screen sizes, and that way your page and images will load faster.
3. Check the Fit a container box (if it's not already checked), this will limit the image size to fit a container size.
4. In the field Classes type
mx-auto (this will center the image) press the TAB button or click on the second field and type
d-block (this will make image display as a block).