(NewsNation) — President Joe Biden confidently closed his third State of the Union address Thursday evening, but as the world watched what he had to say, it was what the president didn’t say that created buzz Friday.

Biden appeared comfortable and energetic as he delivered his speech before Congress. His loud and emphatic speech was sprinkled with humor and attacks on his presumed opponent, former President Donald Trump, in the upcoming election. 

Body language expert and communications consultant Dr. Lillian Glass analyzed the president’s speech Friday on NewsNation’s “Morning in America.“

It took the president about seven minutes to get to the stage, receiving a lot of praise and feedback from his colleagues. Glass believes this empowered Biden, making him feel confident ahead of his speech.

“When he was on the stage, what was very interesting is he was yelling a lot. And a lot of his tone did not match his body language,” Glass said.

Glass felt the mismatch between his gestures and his tone was concerning. Biden was also coughing a lot during his speech, which Glass said was a reflection of how loudly he was talking.

The president also alluded to Trump 13 times, but refused to speak his name once. In fact, Biden called Trump “his predecessor” to avoid saying his name.

Toward the middle of his address, Glass said, Biden’s tone shifted and his body language began to match.

“He started to use more inflection. And toward the end, we saw him a little charming when he talked about his age, and we saw a different president Biden than we’ve seen before,” Glass said.

There was also a lot of back-and-forth between Biden and the crowd. The president ad-libbed a bit, conversing with GOP lawmakers who were heckling him.

“When he engaged the crowd, you could see a different Biden,” Glass said. “He was charming, he was smiling. He was talking to them.”

She continued, “That was very reassuring in terms of how he presented himself.”

Regardless of his confidence spurts, the president did stumble often and repeated himself despite reading the teleprompter well, Glass explained.

“At the end, we saw a lot more charm and a lot more authenticity in his communication,” she said.