Hi,
Although it is an old plug-in, BP-Reshare remains (incredibly) the only way to reshare BuddyPress activities. It works perfectly with Activity Plus, except for one weird issue: if you reshare an uploaded image, and you later delete the reshare, the image in the original post gets deleted too. This does not happen with embedded images, or videos/linkdump. It seems your plug-in interprets the reshare delete as an instruction to delete the uploaded image. Your image deletion routine should be better protected from the deletion routines of other plug-ins.