Dear, 

This is the value of the List item field "Title" related to the Workflow. 

For example, you have a list "A" with 30 items. The default value of the "Title" field is "Site".

It's not related to the Workflow Tasks List.

Cheers...

There is a request on user voice that is about naming of the tasks in the my tasks web part. It's focusing on the task names which I find even more important but you could add your requirement as a comment as it's related and give the idea some votes.

Including Task Name in My Workflow Task webpart – Customer Feedback for Nintex 

Kind regards,

Enrico

Thanks. Upvoted.

Hi Philip,

I'm struggling to see what you mean.

What list? My primary list has title set to the format "{Access Type} ({ID})"

These are site workflows so what list should I be looking for?

Dear Dave,

My reply is related to SP Lists Workflows.

Concerning SP Sites ones, you have to Enrico Knapp reply.

Regards,