In most 4koma manga, the panels are about half as wide as the page, and there are two strips of four panels on each page. Take K-On as an example:
However, Monthly Girls' Nozaki-kun has panels that are about as wide as two of K-On's panels, and each page only has one strip:
Is there any particular reason for this? Is it the magazine it was published in? Is it a shoujo vs. shounen thing? Is it just a random whim of the author?