The new test item was spotted in Eaton, OH and appears to offer the same fillings as the chain's regular quesadilla (a choice of chicken or steak plus 3-cheese blend and creamy jalapeno sauce) but with a diamond-shaped flour tortilla (that seems a little thicker than usual) that is folded in half to form a triangular "slice." It's a little like their Grilled Stuft Nacho but with two open sides.
It should be noted that Taco Bell has offered a "Grande Quesadilla" in the past, which was basically a quesadilla with a soft pillow flatbread instead of a flour tortilla. That doesn't seem to be the case here.
Image via Taco Bell.