I have no idea if I talked about it before Since Jackzen and Alena are not actual dragons, just people shapeshifting into dragons, they can fully stand on their two legs like they would when they're human.
Dragon-shifted-humans have their own unique build compared to true dragons and even Dragon-folk, like their anatomy are still close to human, very small scales that are barely fireproof, plated scales on the chest down to the rear legs, thick skin on the torso, arm, and legs area, spines only at the rear end area, the necks are quite short and not so felxible (though some dragon species may have short necks too, human dragons all have the same neck length), etc. They're three inches taller than their human forms at the withers.
Humans can also characterize some features like the spines–they can choose to change them into spikes, fins, feathers, or fur, horns, and wing shape. They can choose to hide their horns and wings. They cannot however change if they're gonna be a western or eastern type of dragon.
Alena is slightly unique due to not being fully human with her dragonic form tail still resembling her winged form tail, as well as her wings
I doodled Alena and Jackzen beside Lightwing to stand up straight like them to compare Human dragons to True dragons