I hate to sound arrogant, but I tend to do photos that inspire me in some way. Either the color or lighting or the action of the horse. I mean no insult, but that photo is very plain. It will not make a very interesting painting. Your mare is not doubt prettier than shown in the picture, to be honest. If you have a really neat photo, post it. I cannot guarantee being able to do it. I can guarantee that if you commission me to do so, but for freebies for fun, well it's when I have time and when photo "speaks" to me.