@cognoscere, In my opinion you've really had an great walk and all these pictures are loudly saying about that.

And whenever we walk in the nature then for sure the environment always reflects as Healing and gives great refreshing essence.

And yes, that tennis ball is highlighting aspect here because for sure it's reflecting as an effect of Odd One Out.

And yes, Tree Marks always reflects as tattoos and for sure some marks really can amaze us and also can give the natural Artistic essence.

Wishing you an great day and stay blessed. 🙂