I think that they can make your legs look shorter than they actually are, but there are a couple things you can do to off-set the silhouette and overall style of boyfriend jeans. 

• Wear a more fitted, feminine blouse or top tucked in.
• Step into a simple heel that’ll elongate your legs and contrast with the boyish silhouette of the jeans.
• Avoid ankle straps of all kinds. They cut off your legs and make you look shorter.