There are many factors which could have contributed to the differences between the original and replicate figure. The clear difference in lighting could have multiple factors. The time of day could have been different, which would lead to differences in light color, intensity, and the direction of the rays on the plant in the pictures. If the replicate was taken later in the day or early in the morning, that could explain the low light intensity. Weather could also be causing these differences, as the original was taken on a day clear enough for the sun to brightly illuminate everything, the replicate could have been taken on an overcast day which limits light intensity. A difference in camera would also lead to the variation in light, color, focus, and quality of the two figures. A combination of these factors could have also been affecting the different outcomes of the photographs. Unspecific directions in the methods section could have led to different subjects being examined as in panels B, C, and D. Since there was no specifications of the angle the pictures should be taken at, or the distance from the subject this could account for the differences in those features. Not knowing they should have their fingers holding the branch, the individual doing the replicate would not have known to have their fingers included in panel C. If specification was not the problem, lack of thorough reading could have also resulted in the differences, especially when considering two different plants were photographed.
Comments
Repetition
This is an nice and concise abstract that covers all the factors that influenced differences in the figures. You might want reword a couple sentences however that use "could have" because you use that a decent number of times. Overall, great work!
Relating descriptions
Some of the descriptions are difficult to relate for the reader. Under a literary lens the sentences are well worded but from an expository point of view there is some writing that prevents the reader from relating descriptions. For example, "the sun to brightly illuminate everything" versus "limits light intensity", doesn't provide a good basis of comparison for the reader. It is easy to extrapolate what "brightly illuminate" means versus "limits light intensity" but it isn't explicit.
Second sentence
The second sentence states there were "clear differences in the lighting". The addition of the word clear takes a subjective approach to the differences. Try explaining the differences so the reader can realize the differences exist for themselves.