One of the images suggests that the presence of ascenders/descenders makes lowercase easier to read at a glance than all-uppercase, due to differing word shapes

One of the images suggests that the presence of ascenders/descenders makes lowercase easier to read at a glance than all-uppercase, due to differing word shapes. But the text doesn't seem to elaborate further; does anyone know of any studies that support this? I'd be curious to see how the potential for "distinct shapes" affects readability across scripts, considering not just English but also Arabic, Davanagari, East Asian ideograms, etc.