If something is glowing, it's either lit up like a light or it's full of praise and enthusiasm. So, you could receive a glowing candle or a glowing report card. You choose.
When a report or account is glowing, it's unreservedly positive, like a book critic's glowing review of a new mystery novel or your grandmother's glowing praise for the good job you did mowing her lawn. Glowing comes from glow, which can mean "a flush of radiant feeling," and which comes from the Old English glowan, "to glow or shine as if red-hot."