Responsive images
Images in Bootstrap are made responsive with .img-fluid.
This applies max-width: 100%; and height: auto;
to the image so that it scales with the parent width.
Image thumbnails
In addition to our border-radius utilities, you can use
.img-thumbnail to give an image a rounded 1px border appearance.
Image Shapes
Display your images in different type of shapes to carry a better meaning.
.rounded-0
.rounded-1
.rounded-2
.rounded-3
.rounded-top
.rounded-bottom
.rounded-end
.rounded-start
.rounded-circle
.rounded-pill