Light Blocks show when holding barriers and not the light block item

All light blocks are supposed to show in a world when you hold a light block with any data value. However, when you hold a light block, the texture does not appear; only the collision box is shown. See photo below

But, when you hold a barrier block in your hand, both the barrier block's texture, collision box and the light block's texture are shown. The light block's collision box is not shown when holding the barrier block.