It is atrophic glossitis: decreased cell replication= decrease/breakdown of cells on tongue= blood vessels are seen through the thinner mucosa which makes the tongue more red. I would assume there may be some inflammation from the mucosal breakdown as well.
Ya so glossitis can be in iron def anemia, virtually all the b vit def's and some infections (painful, smooth, shiny). The fiery red beefy glossitis tends to be B12.