When you upload an image to Commons, you are not warned when your chosen filename is already used on a local wiki to host another file. Your upload will then show the 'wrong' image if you return to that local wiki. This is confusing behavior
1: check 'uselang' and en.wp repo only for a clash
2: eradicated clashes alltogether and outlaw them
3: make hundreds of queries. Due to the many non-shared repositories being fed by Commons, this is probably very difficult to implement due to performance issues.