Very tough to tell with that photo. He doesn't appear to stand much past the second ring on the barrel, which tells me he isn't that big. I also get the sense he has a small head. When in doubt, I let them go. Ground shrinkage on bears is worse than any other animal.
It can be tough to get them in during the day. Some guys put a lid on the bait at night, and remove it when they get to their stand the next evening.