The report will also not scan any documents included as evidence by the students. When interpreting the reports, this should be taken into account.
This is because it will run using a PDF version of the Workbook (or other resource), which will include 'Hints' included by tutors (instructions, etc.), leading to matches of these between submissions. The Originality Report created in PebblePad will probably be artificially high.
( See here for more details on how to interpret this).