This aura glows the raid frames of players affected by Gluttonous Miasma and targeted by Volatile Ejection. This is typically cause for a healing external if they are on low HP.
The aura works with a sender-receiver system because there is no way to know who the Volatile Ejection is on otherwise. Therefore it will only glow frames of people that have the sender part of this group installed. You can freely delete the receiver part if you do not wish to glow your own frames.
More of our auras: https://wago.io/PescorusCastleNathria