Bears are about the hardest of all animals to judge. I've seen Master Guides in Alaska with over 40 years exp. get it wrong at times. My guess, and it's just that is that it is a mature but still young bear, not a big bear. It looks leggy, doesn't have a huge head. It could be a boar but could just as easily be a sow.
That 3 foot mark on the stick tells me nothing because it's in front of the bear, but you can't tell how far because there's no depth perception in the photo. Also the downward angle of the photo doesn't help. Is this the only bear you've seen during the hunt?
Where are you hunting? Some places just don't get a lot of big bears compared to others. It'll always be a lot harder to judge bears when spot and stalk hunting or even baiting, than it is to be able to look at every angle when they are in a tree.
Good luck on your hunt. I love bear hunting.
