Usually it means someone born and/or brought up in Scotland with English ancestry/origins, or vice versa.
Given the longstanding rivalry between Scotland and England (and antipathy between Scots and the English), being an Anglo-Scot can create problems, especially at sporting occasions, but there are many millions of Anglo-Scots in the UK (including many who feel the need to hide the fact) and no Anglo-Scot is less a Scottish patriot or English patriot for it.
Indeed, in Scotland an Anglo-Scot is as likely to be a Scottish nationalist as they are to be a British unionist.
Only a narrow-minded racist could try and convince you otherwise.
"It can be."