I've seen those. Some use two 1x4's (lumber) with drilled holes set on an angle so you can slip a dowel rod thru to hang ribbon rolls,rolls of wrapping paper,etc. The one like you have pictured has 1x4's also just nailed in -on an angle- with pieces of dowel rods for the thread. Your does look like they have it as a hinged door. But very easy to make, according to DH.