This B-mode ultrasound video clip shows what is called as limy bile in the gallbladder. This organ, though distended, shows echogenic particles and also calculi (stones) of 4 to 6 mm. in its lumen. See this page for more:
The bile in the gallbladder must be a rather thick fluid, almost jelly or putty like in consistency, given that the ultrasound video clip shows almost no motion of the debris in the gallbladder. The overall appearance and echogenicity of the gall bladder is similar to that of the liver, an appearance called hepatization.