Does S3Object.getObjectMetadata() trigger a download of the object?

If I have a S3Object called s3Object and I want to get its metadata like so:

ObjectMetadata objectMetadata = s3Object.getObjectMetadata();

does the call to this function trigger a download of the object from S3? Or is only the metadata downloaded? I'm trying to estimate how much data consumption over WiFi or 3G will result from this function call (I'm guessing its on the order of a few bytes if it's only getting the metadata, but obviously much more if it has to download the object).