[Q] Where a spouse (wife) is applying for a E-2 spouse visa, what are things to watch out for?

Assuming that the wife is applying for E-2 spouse visa based on an already-approved E-2 visa for the principal applicant (husband), the consular officer can always review the facts again and also require that the wife prove that she really is a bona-fide wife by asking for wedding photos, invitations, etc.