Hahaha. Yes I have been on such a train. But in those instances I don't use networks, preferring to use off-line modes instead. I use Lotus Notes as my mail/database/accounts/stock management services, Rclone for filesharing for the stuff I'm working on, I cue up bash scripts for anything I need later (is it just me that uses youtube-dl to get stuff to watch when I'm offline?) So why do we need thumbnails inside large files? Yes the network is the bottleneck and weak link. If it's there, then use it. If it's not then separate thumbnails or data:image URLs help tremendously. I'm afraid you won't convince me that having thumbnails in large files is a benefit. I just don't see the point. Yes, the photos that I take are huge, but when I copy them off my phone I run a simple script to convert them into something useable. for file in *.jpg do convert $file -resize 640x640 "${file%.jpg}_small.jpg" convert $file -thumbnail 100x100 "${file%.jpg}_thumb.jpg" done When they're like this, it's much easier to code for them. Thumbnails as separate files just work. Easier on the bandwidth for when you're on a packed train. After all, once you've started downloading that huge 20Mb image, it's not like it's going to stop unless you switch to a new page.