Hello Dana. The pattern is sometimes called random running bond, in which the horizontal lines are continuous, and vertical grout joints are staggered irregularly from course to course by using various tile lengths. Here, the tile installer increased the amount of 12-inch tile because they are smaller, so we think the quantity of tiles is probably about 60% 12-inch tile and 40% 16-inch. Thank you for your interest.

Thank you so much for your response. The bathroom is beautiful!