Emphasis and Focal Point

Through the use of emphasis and focal point the artist can catch someone's attention. Three ways to utilize this is emphasis by contrast, emphasis by isolation, and emphasis by placement. 

Emphasis by Contrast

By contrast means there is a difference between two parts of the composition that really pops out to the viewer. In the picture below, the area outside the circle is dark and murky colored, while inside the circle Raine has cast is very light and immediately finds the player's attention. 

Shaorina. "Sharpness - Tales of Symphonia Screenshot." Sharpness - Tales of Symphonia Screenshot. N.p., Jan. 2013. Web. 03 Mar. 2013. http://stuffpoint.com/tales-of-symphonia/image/166178/sharpness-screenshot/

Emphasis by Isolation

By isolation, the element is emphasized by being alone. As an extreme example, the man below is immediately easy to focus on due to his being entirely alone and walking in a desert. 

Helgeson, Matt. "GameInformer." Gameinformer. N.p., 24 Oct. 2011. Web. 03 Mar. 2013. http://www.gameinformer.com/games/uncharted_3_drakes_deception/b/ps3/archive/2011/10/24/uncharted-3-rev-dummy.aspx

Emphasis by Placement

By placement, the viewer's attention is focused on the item that is placed methodically in a composition, often in the center. In the center of this picture from Ni no Kuni, the plate of cheese  that is emphasized by the struggle between the two characters pulling at the plate. 

"New Screenshots Emerge From Ni No Kuni." DIY. N.p., 10 July 2012. Web. 03 Mar. 2013. http://www.thisisfakediy.co.uk/articles/games/new-screenshots-emerge-from-ni-no-kuni/P6/