IMHO that means monetary transactions only. No image or other non-monetary data warrants the bloat created down the road on the main chain. Even the Bitcoin white paper doesn’t need to be imbedded in the Bitcoin time chain. Just because something can be done, doesn’t mean it should. It helps to think long-term and all users. Hardware requirements for node runners has already become much more expensive and 3rd world plebs deserve their financial sovereignty just as much as we do.