An object 1) 2) represents an external resource which depending on the type of the resource, will either be treated as:
<object type="application/pdf" data="/_media/iam/auth/ncsc_password_security.pdf" width="250" height="200">
</object>
Example:
<object type="video/mp4"
data="/_media/video/flipbook_within_a_flipbook_flipception.mp4"
width="320"
height="240">
</object>
You may also embed a video with the video element.
See CSS Object (or Replaced elements)
To overcome that the images overflow their container, you can use this rule
img, embed, object, video {
max-width: 100%;
}