Picker placeholder behavior different with dropdown

Hi All,

I found placeholder in picker component defined as "Text to display in the field when it is empty. Does not show if the field is read only."  Ref: https://docs.appian.com/suite/help/25.2/Custom_Picker_Component.html

However dropdown component it is "Text to display when nothing is selected and the value is null." Ref: https://docs.appian.com/suite/help/25.2/Dropdown_Component.html

So when the picker field been disabled or in readonly, it will show blank, how ever in the same page, disabled dropdown field can show the placeholder words. 

Is there a way we can show the placeholder in disabled placeholder words in picker field or anyone knows why dropdown allows to show placeholder when its readonly.