Difference in crystal transformations in the series

A friend and I were discussing the FNC at work today when he brought up an interesting question that I never thought of. In XIII, when Serah turns into her crystal state after completing her focus, the crystal becomes like a sculpture of her body that is see through. Also, if you've played Type-0, when Lady Caetuna releases Alexander and she turns into her crystal, she becomes the same way: her body and cloths become see through crystal. However, when Dazj becomes his crystal in XIII, his transformation is completely different than what we see with Serah and Caetuna. When he turns into crystal, his body is just covered in like a crystal womb and his whole body is there. He didn't turn to crystal, he became enclosed in it. Are there any particular reasons for this? We are both stumped and this is a pretty weird hiccup. Maybe there was an explanation but none that I can remember. I attached videos below of each sequence for you to see. Please give any thoughts its really bugging me now!!


Serah
https://youtu.be/GIPW9Acf4tk

Dazj
https://youtu.be/NuvdyIoglbk

Lady Caetuna

https://youtu.be/QKVJeTblPTk?t=6m45s

Cid Raines also does like Serah and Lady Caetuna. At first I thought it was a difference in Pulse vs. Sanctum fal'Cie, but then I remembered about Raines, who was a Sanctum l'Cie, but didn't transform the way Dajh did. So, unless it was just because Dajh was so young, or some other unexplained reason, I think that it may have just been an error made by the dev team making Dajh become encased instead of transforming.

Yes I forgot about Cid turning as well.
Also I know that Fang and Vanille do the same as they turn into Ragnarok and at end of XIII when everyone turns to crystal its the same as well.

My guess too was just a developemental error but now its driving me nuts.