shady
The expression to throw shade at someone, meaning to be scornful or disrespectful towards them, dates back to American college slang of the 1990s, but it is getting a fair workout in the argument between Megan and Harry and the Queen. Harry was accused of making a statement that threw shade on the Queen, and now it seems that the Queen is sending a bit of shade in Harry’s direction. Along the way it seems that an adjective shady has emerged from the phrase, so Harry’s statement can be described as shady because it throws shade.
Context will no doubt distinguish between shady, as in a tree, and shady, as in a comment, in the future.