I don't know if we can talk about a concept or a style, given the differences between the models.
In any case, only one model is capable of achieving the style I wanted: https://pixai.art/fr/model/1754288030298518365-NW-VXPXL-v15
Trigger words: (girl among flowers), 1girl, tanned skin, (flowery dress), long dress, flowery garden, painting style, persian inspiration
Useful prompts: (persian style flowery dress), long dress, intricate fabric, flower print dress, long sleeves, large sleeves, tiara, jewelry, flowery garden
Negative prompts: cat
Strength: 0.7 -> 1
https://pixai.art/fr/model/1837621795491555778-Floral-V1-NoobAI
https://pixai.art/fr/model/1838814198157215385-Floral-V2-NoobAI
https://pixai.art/fr/model/1873476452770497828-Floral-v3-XLIllustrious/1937244116475330794
NoobAI v1 is the very first version of LoRa but not being satisfied I made another one, still not being satisfied I made the SDXL version and then Illustrious.