photos won't print on the full 8.5 x 11 paper

On my iPhone 5s, photos printed wirelessly to an HP M452dw Color LaserJet Pro printer don't fill up the whole 8.5" x 11" plain paper. I measured the printed photos and they are about 4" x 5". I think that the iPhone thinks I'm printing to photo paper. I'm stuck trying to figure out if it's an iPhone problem or an HP problem. I should mention that I called HP and they referred me to Apple.

Hope someone has an idea for me. I want the images to fit the whole page.