Just testing image uploads -please ignore

[fiddleback]

It seems that any image I insert into a post is scaled to thumbnail size.
This happens even when I select full size when uploading or full size when inserting.
I can click and drag to rescale it, but the result (in the preview) is a scaled-up thumbnail.
I'm suspicious that uploaded files are automatically scaled at the the time of upload.
Also, attachment links don't appear in previews.

Anyway, testing with posts to see what does and doesn't work.
inserted as thumbnail:
upland_woods.png
inserted as full size:
upland_woods.png
inserted as full size and scaled with the mouse:
upland_woods.png

[fiddleback]

So it looks like the image is scaled upon upload, and stored with much smaller dimensions. Funny thing, though. The system increased the file size in the process.