I think that might be D. truncatum, which is short and squat. The colours also look like that of D. truncatum. D. aestivum also has a much longer point and pointed tip on the dorsal sepal, extending well past the hood. Your plant lacks this tip, which is much more characteristic of D. truncatum. The open habitat is favored by D. truncatum, whereas you would expect to find D. aestivum in sheltered forests.