I would like to see daily summary by project, akin to the web interface.
Something like toggl sum projects or toggl sum -o all
AFAIK currently only one project can be fetched:
toggl sum -o stargate_project
There is similar closed issue with a good intention of detailed summary of the day. It was prudently unified since we don't need day, we have -t flag, but the intention is still there.

Sum by task toggl sum tasks would be also helpful and consistent with web interface, even though I personally use summary by project. There is similar useful issue to sum identical tasks time issue.