Hana Hana no Mi gives Robin the ability to grow her body on any surface. Awakening allows Robin to grow her own body (Demonio Fleur).
Differences between Demonio Fleur and Gigante Fleur:
In Demonio Fleur we only see 1 Robin while in Gigante Fleur we see a big Robin and a small Robin(normal Robin).
In Gigante Fleur Robin talks with her small body while in Demonio Fleur Robin talks through her big body.
Also, it explains why Robin has always saved using Demonio Fleur and used it has a last resort against Black Maria. Because Awakened Devil Fruits use up a lot of energy. It also explains Robin briefly passing out/ being exhausted after her fight.
Not only is it interesting the Demonio Fleur bloomed exactly where Robin was and when it disappeared Robin is seen falling from where it was. But the fact that we only see 1 Robin supports the idea that Demonio Fleur is Robin.
Robin also says ‘I’ll become a devil if that’s what it takes’, she doesn’t say she’s going to bloom a devil she says she will be a devil.
The way Robin’s devil fruit works is actually really unique so I’ve been speculating on Awakening with her and I think this is it.
Robin’s devil fruit is the flower flower fruit it’s not the limb limb fruit. Doflamingo has the string string fruit and Katakuri has the mochi mochi fruit. So for them it makes sense that they can turn the environment into what they generate.
Robin’s devil fruit is about growing her limbs/body parts so Awakening allowing her to grow her actual body makes perfect sense to me.