I have a command block set to "repeat," "unconditional," and "always active" that makes all entities glow. However, it doesn't work on minecarts, item frames, or arrows, although it does work on armor stands. Why are some entities different than others?

EDIT 4/28/16: Added screenshots. I went through all the mobs in the game. I couldn't get a good screenshot of the projectiles, but other than that...
All the egg-spawned hostile and passive mobs glow like normal. However, the Ender Dragon and Wither don't glow. Neither do the immobile entities like the lead knot, end crystal, item frame, or painting. Transportation entities (minecarts and boats) are out also, as are primed TNT, falling sand, item drops, and XP orbs.

EDIT 4/30/16: From my manual /effect command (see comments and screenshots) it seems that the game doesn't even recognize that the Item Frame's in existence to make it glow. Extrapolating to the other entities, perhaps the game doesn't recognize that non-mobs are in existence to apply the effect?