Why is it news that Trump was overheard talking to Sondland about "the investigation" on July 25?

Question

According to many accounts of the first day of impeachment testimony, Ambassador Bill Taylor's aide, David Holmes, counselor for political affairs at the U.S. Embassy in Ukraine, overheard President Trump on a phone call with U.S. Ambassador to the E.U. Gordon Sondland, in which Trump asked Sondland about "the investigations."

This one item seems to be the most-reported detail of the day's testimony. What's the big deal? Why would anyone be surprised or find it notable or reportable that Trump talked about the investigation the day after the phone call in which he asked Ukraininan president Zelensky for the favor to "find out about", "look into", and "get to the bottom of", the Hunter Biden thing and the Crowdstrike server thing. This is straight from the transcript the White House provided. Zelensky responded that his new prosecutor would indeed "look into the situation".

Is it because somehow Sondland is not an appropriate party to talk to about it? He was already party to the call, it's not like he didn't know about it. I don't know what Trump was expecting him to do, exactly, as Ambassador to the E.U. and not to Ukraine, but still, I'm not getting why this particular detail is so notable.

Is it because nothing at all was notable about the day's testimony and the press had to come up with something to report on, with all the interest and attention on the proceedings?

Answer 1

This particular item is receiving so much attention because:

1. The transcripts of the closed-door testimony of both William Taylor and George Kent had already been released, and their public testimony was expected to be (largely) the same. Regardless of what you think about their testimony, the fact that a new key piece of information came to light was novel and unexpected.
2. If the report is accurate, this call would tie the President of the United States directly to the scheme. Trump can't plausibly claim it was his advisers "going rogue" or something.
3. This new information directly contradicts Sondland's sworn testimony to the committees (which he's already revised once), further impacting his credibility. Sondland is scheduled to testify next week; he will surely be asked about this discrepancy.
4. A call to the President of the United States from an unsecured cell phone in the middle of an open restaurant in a foreign country has been called a "stunning breach of security", and would likely have been a notable news item regardless of its content.
5. Sondland's post-call remark that "Trump cares more about the investigations of Biden than about Ukraine" goes directly to whether Trump had corrupt motivation (that he cared about the benefit to his 2020 campaign, and not about Ukraine reducing actual corruption), which might otherwise be difficult to prove.

This is the key accusation of these impeachment hearings: that the President of the United States was corruptly using the levers of power for his own personal gain (advantage over his 2020 opponents) rather than using them to advance the foreign policy and security priorities of the United States.

Further details and analysis:

• Trump Directed Diplomat to Ask Ukraine to Probe Biden in Overheard Cellphone Call
• Taylor says staffer overheard Trump ask Sondland about 'the investigations'

Answer 2

President Trump will very likely be charged with a number of impeachable offenses, including bribery/extortion. His most current defense as of 11/14/19 13:29 EST is that there was no actual attempt at a timely exchange of services: that Ukraine had to investigate Hunter Biden before the military aid would be released. They were just two separate thoughts on the same phone call.

By Trump following up the next day on whether or not the Ukrainians had started their investigation, it gives a window into Trump's mindset, that he expected that the 'stick' of lost military aid would motivate the Ukrainians to begin their investigation into Joe Biden the very next day in order to have the aid delivered on-schedule. If his request was simply an offhanded one of little importance to Trump and had no contingent effect on whether or not Ukraine received the aid, Trump would have waited weeks or months to see if Ukraine did what he asked.