If narrow motive details are displayed as a sharp, for example a pixel wide lines, one can be satisfied with the sharp. The narrow light edge around the dark pole in the 8-fold enlargement shows that the camera has already shoved internally here
Jpeg photos recorded by a good digital camera with medium apertures are already internally "advised", here is hardly something to improve. For unparalle pictures from a professional camera, for example in RAW format, this does not apply; even if photos are enlarged by hinging pixels (interpolation), rewrapped.
In addition, in addition to the objective sharp also a subjective "tricky" sharp. For the latter, the overholding of the edge contrast plays a role. A less sharp picture with thickened edge contrasts can therefore be perceived by the eye as a sharp one as a sharp picture with unpleasant contrasts.