APS-C Vs. Full Frame: Can you Guess Which Photo Came from a Crop Sensor?

If there’s one single item on a camera’s list of technical specifications that indicates image quality, it’s the image sensor. Yes, the processor plays a role here too, but the sensor, the mini semiconductor that’s capturing the image, is the biggest determining factor in how images from the camera body look. And, more important even than megapixels, is the sensor’s size. But, just how much does size matter? Can you tell when a photograph was taken with a crop sensor and when it was taken with a full-frame sensor? Without looking at metadata, can you pick out APS-C Vs. full frame just by looking at the resulting images?