...
There is only one embedded object in the worksheet.
There is an explicit alert that an embedded object is present.
Instructions for how to access the file and how to return back to the cell layer are present.
The type of file and the contents of the file are made explicitly clear in cell A1.
Section
...
6.7: Flashing Content
An Excel workbook must not have any content that flashes more than 3 times per second. Lots of flashes can be triggering for people who get epileptic seizures.
...