Its the rolling - she is "throwing" herself to the floor - pushing - then jumping up - then going down and rolling again -- this is not normal (compared to the foalings I have observed) -- I see they have her up now - and a nice bulge - hoping that the foal is correctly positioned.
If the cam goes off for you, try refreshing your browser... worked for me. Gosh I hope everything is ok! I thought I was just in time to see a great foaling before getting back to work on a paper. Prayers for the Momma and her soon to be little one.
I appreciate it that they have not turned off the camera -- this is quite the learning experience. Know we can't help them (other than by Praying) -- but sure can learn a lot.