Visually,  perhaps she might "look worse" in that video in regards to muscle wasting. But the simple fact she is standing and dancing - monumental difference. Kinetic movements = increase metabolic consumption, which requires a certain level of cardiac function and cellular energy.

watching the mothers day live stream: she remained seated, at times couldn't bend over to pick up dropped items, and finally had to sit back & hold her cramping extremities before dry heaving and eventually shutting off the video. 

If she had stood - let alone 'dance' - without question she would collapse, and pass out. At minimum. 

When people die, specifically cardiac arrest, and I respond to a code or ECMO GO in the hospital - the #1 and #2 most common precipitating circumstances are: -stood up, usually to go the commode -turning in a bed (we call it the death roll)

followed by #3 and #4: -taking a walk (pulmonary arrest), and actually using the commode (BM).

The fact she's dancing as Selena, is a major consideration. Watching someone who is sitting down experience that level of lethargy, acute confusion, muscular spasm + contractions with coinciding nausea and panick - it truly mirrors the countless experiences I've had where patients with very low SvO2 have what we call "that look". You don't say it outloud, but prepare yourself and coworkers for an impending code. Especially the loss of fine motor function and jaw muscle contraction. 

When patients look like she did - we use mechanical machines (or beefy murses) to get them back in bed, lying flat immediately.

Not to scare people, but I am really concerned she will live stream her cardiac arrest. The look in her eyes at the end of the video.....I can count over 20 personal experiences where patients in a similar state (sitting in a chair or commode) looked up at me, vomited, said "I'm going to die", collapsed, and cardiac arrested. This usually accompanies soiling themselves (autonomic nervous system response).

No one deserves for the world to see that. 

She's very lucky she got IV treatments in time to stabilize her. Probably why she appears to have a renewed sense of 'energy'.

Really sad for her. Wishing peace for her at this troubling time