Everything we do/type on Steemit is on the SteemIt blockchain....your posts are on the blockchain...your comments are on the blockchain...so any images you've uploaded are also on the blockchain & can be found where ever you post them & I think that's what the person telling you that meant. As for moving a site/business onto a blockchain, one would need to know/understand the differences in the types of blockchains out there & decide if they want to build onto that or create their own (you need real pros to do this or be a programmer type yourself). For more in depth you'll prob need to sit down with google for a bit as it would take too much time to get into what you're asking I think. Good luck!