You've got the overall feel of the hrose. He seems to have a heavy muzzle and smallish eye, but that could be that the photo was taken from an upward angle, which would make the perspective create that look.
When in doubt, I always err on the side which makes the horse look a little nicer. I know that's cheating, but I give it the benefit of the doubt that the photo might not be the very best one.
If you screw up, use tracing paper to copy the good parts, make adjustments, the take the tracing paper off, turn it over, and use a pencil or graphite to darkent along the drawn lines (on the back of the paper) so then you turn it back to rightside up, place iton a clean piece of paper and draw over the lines again. THsi pushes the graphite on the backside of the tracing paper onto the new page, transferring the image. Then you get another go at it.