All-star is one of lol championship and it takes place every year in different cities. The background with beautiful scenery shows all-star held in Barcelona in 2016.
Background with Eiffel Tower and Arch of Triumph adds a feeling of historical for the poster. Besides, this year's logo is distinctive because it demonstrates the landmark.
This poster is more like a advertising board with all-star logo and where it took place.
LOL world championship is popular in the world. This poster uses Tower of London as part of background to represent blue inhibitor (related to the game).
Similarly, this poster uses Eiffel Tower as part of background to represent blue inhibitor.
I am not sure the place in the image, but it is also a nice picture with strong contrast colour. It represents league of legends is popular all over the world.
This is 2014's poster, with same logo and silhouette of championship.