Location mostly, the first picture looked a bit wet. Roosevelts tend to "crown" a bit more often when they're allowed to age a bit, the tops can be a little more Red Deer looking. Shorter main beams usually. Horns and bodies always look a bit darker to me.
A lot of genetic diversity though. Local zoo closed years ago and they were turned loose north of town so they've combined with the rockies. Claims are some of the high fence folks have lost some of their stock over the years as well.
If you're hunting in hip boots, or waders it's likely a Roosevelt. I always claim Roosevelts have webbed feet, and gills, but that's probably overstating it a bit.
Bodies are usually bigger, could be habitat and no winter. Some of the old cows will get pretty dang big. Some of the islands they transplanted on have recorded some big bodied bulls.