I've never seen any other "miniature" crown like hers. Was it an original, bold fashion move, or an already existing traditional type of crown? I think it was a clever idea but it could have had a bad reception and her image could have looked cartoonesque for most people.
It was a compromise. After the death of Albert she chose not to wear the heavy, colourful, imperial state crown. Instead she wanted something that could be worn with her mourning clothes and so this smaller crown was designed for her. It may have been based on previous nuptial crowns which Royal brides would have worn over their wedding veils.
As to it being potentially comical, her subjects would have recognised it being part of her mourning attire, so they most likely would have understood the reason for it being so small and relatively modest, as far as crowns go.
Victoria was certainly capable of being risque when it came to fashion in her youth (the loose hair, exposed shoulder portrait for example) but the little crown was a much more sombre affair.