Workshop or follower of Santerre - "Louis-Joseph de Bourbon, duc de Vendôme" - Blois

So-called Portrait of Louis Joseph, Duke of Vendôme (1654-1712)), but is probably a depiction of Louis, Grand Dauphin (1661-1711)
Identification proposed by user Ecummenic (talk) based on the comparison with some portraits of the Grand Dauphin (see image below) and the absence of physical resemblance with the Duke of Vendôme.