My interpretation of this performance aligns with the idea that the song is about rape and rage, as stated by Gaga herself.

If you know someone that has suffered through some form of abuse and experiences a traumatic response (e.g. post-traumatic stress disorder), you'll know that it's not pretty. In some cases, this manifests as self-harm in various forms that could include binge-purging.

Together with the intro to the show where a girl was perhaps binging on sausages etc, I think this performance was meant to represent the following narrative: 1. transgression (e.g. rape), 2. rage (e.g. bulimia, self-harm, calling the perpetrator a swine and feeling like a swine yourself) and 3. recovery - hanging up the vomit like a canvas for all to see in the form of art.