Responses
Actually it's becuz,of the attitude of aria when they met since u know for people aria is indecent so they thought it wouldnt be aria plus he also saw the carriage that has the roscentes crest yeh and also the dress ig dont remember much be he does say that in the later on story
If i remember correctly, the crown prince (assuming its the blue haired dude from way chapters behind) didn’t exactly know that Aria is also the daughter of the count. Since when they first met, Aria was wearing Mielle’s dress after burning all her clothes ‘in an accident’ and have blonde hair like Mielle. And since Mielle is the only known daughter of the count, im guessing he assumed Aria is Mielle, hence the gifts for ‘Lady Mielle’
On another note, the Count is an outright bastard for not doing Aria any justice. To take her ideas, use it and give Mielle the credit showed not only favoritism but how he sees her as just a tool to be used. I cant wait until Aria would make them suffer and show her ideas and be recognized for it.