Oh, that hurts to look at! What once held water for slow-release into the tree's root zone has become a container trapping mulch up against the bark of the tree. Disease will ensue.
Sadly, this isn't a unique incident of arborcide; I spotted a whole block of them in a D.C. neighborhood near me. Names on the Treegators give credit to the D.C. government and local nonprofit Casey Trees. A return visit is in order, doncha think?
Addendum: This is NOT a Treegator product and some alert person there corrected my assumption. Sorry, y'all.