I use a tiling WM too (ratpoison), so I empathize. But you don't need to launch a file manager in order to drag and drop. You can open the image file in another browser tab, and then drag it between tabs. Hover over the destination tab for a moment to pop it forward.
Edit: It would be useful to make an addon that adds a contextual menu item for "Drop file here", which raises a file selection dialog and delivers the result to the drop zone. Essentially it would be the inverse of this: https://addons.mozilla.org/en-US/firefox/addon/ez-drag-n-dro... I don't currently have the time to write it.
I never really thought to do that, so thanks for pointing it out. It may come in handy one day if I absolutely must use one of those services.
But in general, that's still awkward, and enough of a (mental) hassle that I probably won't bother if it's just someone who wants me to check their site out. So my advice to any web designers would be to make sure your site is functional even without the flashy add-ons, the same way you would make sure your site is functional on all browsers/operating systems.
fuzzix said it best. Long ago I configured ratpoison to be modal like vi, with tons of personal customizations. I've set it up to behave exactly like I'd want any WM to, so what's the use of moving to something newer?
Edit: It would be useful to make an addon that adds a contextual menu item for "Drop file here", which raises a file selection dialog and delivers the result to the drop zone. Essentially it would be the inverse of this: https://addons.mozilla.org/en-US/firefox/addon/ez-drag-n-dro... I don't currently have the time to write it.