Starting from the open major chord, a successive change in timbre is achieved by moving a single finger, i.e. new intervals are added to the chord. From column to column, the result is:
1. column ↓ major chord
2. column ↓ major 7th chord
3. column ↓ dominant 7th chord (mild)
4. column ↓ major 6th chord
5. column ↓ dominant 7th chord (spicy)
Even if the girl at the lake in the video is not yet impressed, these chords already sound very pretty thanks to the ornaments with a picking pattern in 6/8 time. Just don't give up!