XF 2.0 How do I add 2 pictures to the sides?

[Jake Sully]

I would like to know how can I add 2 different or same pictures to left and right side of style? I'm currently using https://xenforo.com/community/resources/default-small-style.5689/ as theme but it's empty to left and right areas. So I hope some 1 here can guide me what todo to add 2 pictures there that stays on scrolling.

/Thanks