In AD it is possible to add company branding to your office 365 sign in page under the tab "Company Branding" in the AD. However i have seen some organisations "move" the dialog box in which you input your login data. See example below: Anyone know how to do this? or is this even possible? :)
Not sure what exactly you mean by "move", but the screenshot looks like it's from an on-premises AD FS install, not O365. In other words the login process is being redirected outside of O365, which in turn mean you have more flexibility on what elements you can edit on the page.