I have to agree that Delphine deliberately wears the outfits for these occasions for the attention, she stands out.....and as a flip off to the Royal Family and the rules it abides by.
Delphine thinks she's entitled to be on an equal footing with her half siblings...doesn't work that way. All these years I'm sure her mother has been whispering in her ears that Delphine "deserves" to be treated "equally". Nope, she may be King Albert's illegitimate child, but she had a legal father. Sorry.