Antique Feeding Cup
It’s certainly understandable why this person thought they’d stumbled onto some sort of odd little teapot. With a handle and what appears to be a spout, this is actually a feeding cup. They were used for those that were too weak to feed themselves. The spout can almost be thought of as a straw but of course, the cup does need to be tipped.
provided by constative.com
The covered piece assures that the liquid flows towards the spout and not out, and over, the cup. A handy invention, in the past decades this cup has been replaced with lids and plastic tools which also help assure that it’s not accidentally broken. It could be a lovely addition for an antique cup collector.