This may be old news but if helps one person, then good enough. I was in the motorcycle niche for a while. People LOVE their bikes, especially Harley Davidson. I was manually posting bike pics 2X per day from my phone with accurate descriptions to make the account look as real as possible. I'd go to CL's motorcycles for sale section, search for Harley Davidson and the pics and descriptions were right there. Download the pic, post it with the sellers provided description like "Awesome 2013 Custom Fatboy" and a bunch of relative hashtags. Definitely not the fastest method but I got a nice pic and description every time. CL maybe worth a look if you want to harvest some pics for other niches ......
interesting method and definitely something that can be automated so you don't have to do that manually ( it might work for 1 account but it will be a killer for hundreds of accounts ).thanks for sharing.