Diddy's trial has focused a lot on drugs and drug usage over the past few days ... including when Cassie's friend Bryana Bongolan testified that she previously purchased drugs for her -- and pictures of what appear to be drugs have now been entered into evidence.

"I was scared to fall," she recalled on the stand, adding that she had no idea what prompted the outburst. "You know what the f**k you did," Diddy allegedly shouted, according to