[geuis]

"Now, it should be clear that most of the time (28s-53s on the time line) of importing that particular USD file is spent in id_sort_by_name".

Luckily there's a graph screenshot. But the graph it displays is incomprehensible. Without "id_sort_by_name" being on the one bar, I wouldn't even know what I'm looking at.

[wtallis]

The timeline view in the upper screenshot is fairly straightforward: the region of 28-53s is selected, other parts of the timeline are grayed out, and the statistics for the selected time region down below show 94.4% of "Total CPU" being in id_sort_by_name.

The lower screenshot is a flame graph. If you haven't encountered one of those before, it's totally reasonable to not know how to read it. But it's a standard and common way to present this sort of data. See https://www.brendangregg.com/flamegraphs.html for more information.