"Bliss" is quite a strong word because it can mean a state of perfect happiness. But Dickinson calls it a "daily bliss" meaning it can or does happen every day. This sounds like Heaven on Earth, but she then adds that she experiences it "half indifferent" which means that she does not care about half of this blissful experience. Therefore, it is not perfect happiness. It is halfhearted happiness, whatever that amounts to in her intentions. And since it is "daily," it is something that she probably takes for granted. In other words, it's easy to take something for granted if it happens every day.
She then perceives this bliss to "stir," to move or change. Physical or abstract, it is away from her already because she adds that the bliss grows as she pursues it. That initial indifference starts to dissipate and the bliss, or the allure of the bliss, starts to increase. The elusive bliss disappears from her sight. And it is only then that she truly understands and appreciates it. "I learned its sweetness right."
Concluding that the poem illustrates the idea that "you don't appreciate what you have until it is gone" really just scratches the surface of the meaning. Dickinson's more significant meaning is that it is the pursuit of bliss that really sparks genuine feelings of happiness. There is pain in chasing happiness and not reaching it, but there is also the exciting allure of the pursuit. One might draw other analogies from this. For example, the anticipation of some event is more exciting than the actual experience. Or, the desire for something elusive is as, or more, powerful than actually having the desired object or person. After all, desire requires that the desired object be absent or out of reach. In this respect, one can read this poem as an expression of spiritual, sexual, or romantic desire. But since it might also be a "daily" bliss, it could relate to something quite ordinary as well.