Meghan Trainor's All About That Bass - the real chords

It's funny how things can get changed in translation, one of which has got to be the various versions of Meghan Trainor's All About That Bass.  Where she belts out the song in YouTube vids and she has no ukulele it could be anyones best guess as to what chords the song is in. But, and it is a small but, you can actually see for yourself by watching another video of Meghan sing this with her own ukulele, and let me say this, 90% of the YouTube videos teaching how to play this song have got it wrong. 
It is a matter of checking out Meghan for yourself, freezing the frames and looking at how she is holding the chords.  Let me categorically state, there is no A chord in the song. So those who think there is, go and get on your bike and take a long ride of a short pier, then watch the video for yourself while drying off with a big fluffy towel. For you will need the towel.

So here are the screen captures of Meghan Trainor's hands as she forms the chords, the first one is clearly a G chord. However the placement of her thumb on the G String, suggests she alternates between using a good old G major and a G add 9.  It is difficult to tell but as a first chord this looks absolutely nothing like the predicted A chord on so many YouTube videos.  I checked out this configuration on a chord finder web site and took the assumption Meghan is playing in the normal G, C, E, A uke tuning.  What however is an even bigger puzzle is the second chord Meghan uses.

Here it is:

For some reason this chord does not come up on the chord finder, it actually is not a defined chord. Saying this, I guess if you know how to play music and it sounds good the music you play does not have to be dictated by text books.  Maybe it's what makes Meghan's song sound great. I blew up this picture just to show what I mean.

The last chord picture is here on the left.  After watching the video a few times I come to the conclusion this is a D7. Megan is using her thumb to seal of the second fret of the G string. I noticed as Megan played there were moments when she flicked her wrist down after holding chords as though they were uncomfortable and she was giving her wrist a momentary break. I might be wrong in this, it could be she is adding theatrical emphasis on the beat, but in my opinion it's a wrist break because of minor discomfort.

YouTube videos are interpretations by those who post the videos of what are the true chords and beats of a song.  I've got to understand this a lot more as I've checked more and more tutorials.  There would be a favourite youtuber for me who seems to get it right but then they will do a version of a song and it just doesn't hit the spot. In which case I choose to move onto another person or even try a variation on the their interpretation so as to bring the chords or strum pattern closer to what I think the song sounds like.

When it comes down to it there is no right or wrong, there is only the method which gives you the most fun.  Because it's all about the Bass, the Bass no Treble.