I've watched some videos from Salesforce viewing that Marketing Cloud is integrated within Salesforce.com. Here an example:
How is it possible to do that? Marketing Cloud Connector do not give us this function to integrate it.
Regards
Unfortunately, Lightning is not currently supported via the native connector , Marketing Cloud Connect.
If that was an official Salesforce Vid, then they are covered by the "Safe Harbour Statement" ... "Forward Looking Product Demo..Do not base your buying decision on it "
Excerpt from the docs :
Lightning Experience is not supported for Marketing Cloud Connect features. Those using Lightning Experience in Sales or Service Cloud are automatically redirected to Salesforce Classic when any Marketing Cloud Connect tabs are clicked.
Resources: