I think it might (?) be a new thing with dropbox or that what you have to share needs to be set up as shared publicly. I don't really know. I don't use dropbox. However, I have noticed that for the last few months it gives a prompt to login if you want to view or download anything via dropbox.
Thank you for sharing the photos. Going off of what I see it's not the actual object that is off center it's the light source. That could be caused by a lighting mod. Though I am not sure as I don't use them and never have.
I jumped in-game to see if I could help troubleshoot. Here's a photo from my current game. The light source seems to be okay.
Click on image to enlarge.
So something is definitely not quite right in your game. Something to try is doing a factory reset, take the family/house into a new test game without mods and/or custom content to see if that helps.
Sims 3 Factory Reset (What & Howto)
http://www.carls-sims-4-guide.com/forum/index.php?topic=20732.msg401814#msg401814