No — they do different jobs, and it's worth being clear about it.
The Practice Workbook contains ten self-scored mock tests. They are cue cards, framework grids and self-scoring boxes: you record yourself, then assess your own answer against the criteria and the model answers provided. That's practice, and it's included in the ¥88 book price.
A mock test on this page is marked by a former examiner. Mike conducts the Speaking interview live or reads your written script, and returns a band estimate against the official descriptors with written feedback. That's assessment, it's a separate service, and it's booked and paid directly with Mike.
Most candidates use both: the Workbook to build the habit, an examiner-marked mock to find out where they actually stand before test day.