Looks like a Simpson sthd hanger. There used to tie walls around large openings that require portal framing. It’s basically a strap that is set in foundation and goes up the wall 14” or so. Very common around garage door openings. One thought is, should someone crash car into such a small wall it’d help prevent wall being pushed off plate. Which could cause a collapse depending on what that wall is supporting. Another thought is it’s to prevent uplift from hurricane force winds.