[packs]

Baseball-Reference is showing that there were 38 players on Cleveland's team in 1911. So if this photo is from 1911, there is a 1 in 38 chance that it is Jackson. Personally, the photo is so hard to see I don't think you could really make a determination. But purely gut feeling tells me that Jackson looks like a baby in his T5 and that guy sliding into third has the look of a grizzled veteran to me. It also looks like th sliding player's stirrups don't continue to their foot, while both photos of Jackson show him wearing stirrups that go all the way to his feet. Although that could just be the angle.