So, what makes the second request to the magistrate, different that the first, denied, request?
The first request was probably too broad... "All Trump related phone lines, accounts, etc.". They probably narrowed it somehow... and juiced it up with more "compelling" language about "national security" and so on.
You take a monthly total of hotel room payments from Russian guests across dozens of properties (rooms are $500/night and up at most Trump hotels) and add in charges for guest activities (booze, massages, etc.) and you're going to get some impressive numbers.
Go to a judge and say "look, in August we see payments of 12 million dollars from Bank of Moscow going to a Trump server" and you have something that sounds impressive.