Like that it's casual on the grass, the chairs are natural wood with padding, the table cloth is off white and possibly linen, the heaters are scattered, the tent has sheer drapes and the centerpieces are small and simple. I would only add more lights up top.
If you have a line of trees such as these this would be a great idea for you in your backyard wedding. In the middle of each tree have a table and chairs and line the trunk of the tree with as many fairy lights as you can. They give off such a lovely ambience to your wedding ceremony outdoors.