Party etiquette: Is this excessive?

My cousin is throwing a birthday party for her husband. The invite states they are providing meat and that people should bring “a side and a dessert”. She doesn’t always post the most coherent things, so I assumed she meant being a side or dessert. Today, she posted asking for RSVPs and stating that everyone is expected to bring two sides.

Does that seem excessive to anyone? I understand asking people to bring one side...but two? I personally think for a birthday party, you should just want people to attend and socialize. 🤷🏼‍♀️

I won’t be attending, but it just sounded weird when I read the post.