Interesting Horse Behavior

Today I witnessed a very interesting an sweet interaction between my mare Phoenix and her foal Elsa. I was in the pasture working on teaching Elsa to lead with her rope halter. They were standing side by side and Elsa had decided she didn't want to move anymore. I was observing her and being patient when she began licking and nibbling her mom's lips and muzzle. At first I thought "oh she's just showing affection or she's checking in with mom" But then after she stopped, Phoenix went to Elsa's rope halter to the exact area it was tied and proceeded to spend several minutes trying to untie it. I watched and thought about it and it was as if Elsa had actually communicated with this little nibbly language, "Mom I am bored with this human game, can you remove this thing so I can be done with it?" I was so entertained by this and the precise way Phoenix stepped in and "tried" to free her but in the most relaxed peaceful way until she realised she couldn't do it. When this interaction played out fully, I coaxed Elsa forward once again. Telling her if she could do one more step, I would relieve the gentle pressure she was trying to escape. She finally complied and I removed the offending rope halter immediately to reward her and gave her a good scratch which she loves and will gladly stand for. I just love being able to see something like that, and it makes me wonder what I may miss when I'm not there...