This is a video from May 2009 of President Barack Obama going to a Five Guys to get some burgers to go. In a way, this was kind of a stunt. NBC was shooting a day in life of the Chief Exec — you'll notice him ordering for Brian Williams — but it was also a nice moment to see the Leader of the Free World mingling with ordinary folks. He was cordial and approachable and he talked to everyone he could, asking most of them about themselves and their occupations. He did this kind of thing from time to time.
Can we imagine Trump doing this? Sure, though he wouldn't be in shirt sleeves and the only conversation would be him telling everyone how successful he was. And then for days after, his speeches would be about how everyone told him what a great job he was doing.