Shoutbox

What you see in the conversation window when you share photo's are indeed always lower quality versions of the photo than the ones you 'save'. What you see are always down-resized thumbnails.

This is on purpose to save bandwidth and speed. Most people do not need to have the full blown big sizes to simply see a holiday snapshot of a contact (photographs taken with a camera are these days +10MB big and have sizes ranging to 2000 pixels or what not; even too big to show on some screens). And that's the biggest reason why the current system of Photosharing has been created in the first place.

If you would tamper with the compression (eg: you disable it completely) by patching Messenger for example, than it will take as much time to share your photo as it would have when you 'save' it in an unpatched version. There is no way around that.

Another possebility to show your contact the full size version is to not use Photosharing in the first place, but sending the file directly (like you would send another, non-picture, file). But again, that wouldn't be any 'faster' either though, for obvious reasons.