Bond with nature in this charming expansion pack means...

I do think it has something to do with farming - not the cute way with fantasy farm. I think it may be corn/wheat etc., maybe chickens, maybe vineyards? And hopefully there's some family gameplay.
I think of the charming element to be those pretty but cozy farmhouses with flowers and beautiful nature surrounding them.

I might be wishing for a little too much, but charming and bonding with nature can, from my IRL point of view, be exactly this!