they stand up and chant with 3 fingers at 1:52:20
just before that Nancy had given a kind of sign or said something to someone on that side
it seems to relate to big pharm drug pricing
here's something on that moment
"When Trump urged lawmakers to send him a bill to lower prescription drug prices, promising he would “sign it into law without delay,” some Democrats leaped to their feet and, holding up three fingers, began chanting “H.R. 3! H.R. 3!” — an allusion to a House-passed bill that would help do just that."
https://www.washingtonpost.com/politics/2020/02/05/d2db682a-476d-11ea-ab15-b5df3261b710_story.html
at 1:51:40 Nancy mouths "H.R. 3" to her group and then less than a minute later the ladies in white stand up yelling HR3