The main difference between the two figures which is the addition of panel D in the replicate can be explained by the creator of the replicate not fully reading the methods section. There is no mention of a panel D anywhere in the methods section only three panels a, b, and c were described. If the creator of the replicated figure did not fully read the methods it could also explain some of the other differences that were observed between the two figures. It could also explain why some of the figures were labeled the wrong letter. However, while misinterpretation and not fully reading the methods can explain some differences there were some faults in the methods section itself that lead to the differences in the figures.
Comments
Avoid Judgement
Calling something a "main" difference is using a judgement, just refer to it as a difference
consistency of capitalization
If the D in "panel D" is gonna be capitalized then be sure to capitalize "a, b and c"
Assumptions
I would avoid assumptions as well. But overall, well written.