If a blazer can't be casual, then who said that?
The oversized beige jacket that is worn over the graphic t-shirt that is combined with the relaxed-fit jeans is the focal point of this ensemble.
The ensemble is finished off with black shoes with pointy toes and a large bag, which creates the ideal combination of casual and business attire.
When you wear this sort of clothing, you are sending the message that "Yes, I am cool enough to wear jeans to the office—watch me!"