Given great enough distance, I see a tiny mirror eventually acting like a pin-hole camera.
While in elementary school, I had a broken piece of mirror (maybe 3-in by 1-in) and it reflected the light from the sun in the shape of the broken piece onto a nearby wall.
However, the further I projected the reflection the more circular it became and the larger the image (so even in this distance it was acting as a pin-hole reflection)! (This also works for a solar eclipse, cast the sun's reflection on a house (which is of course shaded) maybe 200-ft away, go and examine the image (inverted as through polar inversion), and you'll see a large and good resolution image of the eclipse.)
Therefore, if you reflect the image of the sun back to the sun, even with the broken piece, the light arriving at where the sun was before it had moved (due to the Earth's rotation and the time it takes to arrive to us) by travelling the same distance would be the same size as the sun.