Hi @acvigue
you are on the right track regarding the photos, but you may try to create a more consistant picture language:
The photo showing the UM robots is the best one, but even the robot in front is not in focus. You should have at least one item 100% in focus.
The gear box photo is almost perfect, except of the white balance. Try to always get the same “shade of white” in the background on each photo.
The screws are ok, except of the white balance. The background is a blueish grey
The fish is the worst photo. It is noisy and the white balanace is not good. The background is a yellowish grey.
Hope this helps.
Cheers,
Joerg
EDIT: Today it came to my attention that you might have copied one photo from here: Knurling bolt and nut by akira3dp0 - Thingiverse 1
If that is the case, I strongly recommend that you ask the owner for his copyright, and/or make your own photos.