Seven Hills Of  Lord Venkateswara Meaning

According to purnas Adi sheshu is equivalent to seven hills of the Tirumala Tirupathi. Adi seshu will be shown as seven headed serpant on whom lord vishnu will be laid. Similarly the incarnation of Lord vishnu , Sri Venkateswara Swamy of Tirumal Tirupathi will be residing on the Seven hills. Also you can observe in the photo placed below which get after rotating seven hills photo.  It is clearly observed the face of Lord Venkateswara with nose lips and chin can be observed. 

Further Visually explained in the following video