What is the first thing that comes to your mind when you think of the word repetition? 
A piece of music perhaps, that just seems to go on and on with the same of boring uninteresting rhythm? Or an unimaginative child is colouring in a picture and picks out a nice blue for the sky, but also uses the same colour for the grass and for the entire family picnicking on it.
I suppose if you photographed a piece of cloth that was white with red polka dots all over it, that would not only be repetitive, but also very boring.
But repetition in photography can also be dynamic and exciting.
Take, for instance, a line of coloured beach bathing boxes, although they are all pretty much the same shape, strung out along the same bit of beach and shoreline, their redeeming feature, photographically, is the repetition of their vibrant, alternating colours. This makes their repetitiveness very dynamic and exciting!
Another example of repetition could be a photograph of rocks in a dry river bed. Nothing but rocks! But rocks are never the same shape, nor are they likely to be exactly the same in colour or texture, so the pattern they form, their shapes and colours make for interesting viewing.
Footprints disappearing off into the distance on an otherwise undisturbed beach. The beach scene itself may be boring, but the repetitive line of footprints add interest and impact, particularly if they all head off in the opposite direction to the photographer.
So, unlike some music, or some web sites for that matter, repetitive elements in photography don't have to be boring. They can also be used as leading lines that draw the eye of the viewer into the scene. Like a line of trees, a line of fence posts, or even a line of footprints in the sand.
You are only limited by your own imagination. Have I said that before?
I hope you don't think my site is repetitive and boring!