It's a bucket with the words "Mount Eerie" swooping through the handle.
The bucket is ancient, from an archaeological dig in Denmark.
The emptiness in the bucket is even more ancient.
The garment was made totally in the USA out of 100% cotton by Bayside and masterfully printed in Anacortes by Paul of Granular.
(Image is pretty big on there. The shirt in the photo is a "large".)