First of all, is there any reason why this test is not combined with the isPrimary test (pointerevent_pointermove_isprimary_same_as_pointerdown.html)?

Assuming there is, there are several issues with this test.
1. The test layout and structure are very different from the other tests. In fact, it reminds me of the previous version of those tests.
2. The explicit_done option is used but no done() statements are in the test file.
3. The test at L50 should only be performed when the pointerId of the pointermove event matches the pointerId of the last received pointerdown event.
4. L54 should be a simple done(), since the whole point of this test file is that single test in L50.