Two Different Uploads
The portrait photo and the passport data page are separate files.
A Vietnam e-visa application asks for two images: this 4x6cm portrait photo, and a separate scan or photograph of your passport data page. They are not interchangeable, and uploading the passport page in the portrait slot is one of the most common application errors.
The portrait is the one that has to meet the photo rules — white background, no glasses, no hat, neutral expression. The passport page just has to be legible.