Currently, calls done in the same event group (consecutive instance of the same category of events within a restricted amount of time) are added as small icons. It works best with 3-10 calls in the same group, but isn't useful with a single call or a large amount of calls. At some point you get a huge rectangle with dozens of icons. Hopefully it never happens "in real life" since the odds of calling the same person dozens of time in a row isn't worth considering. However that leaves the single call case, which is by far the most common case. This alone makes this bugs worth fixing.
Not pixel perfect, but functionally done.