[janko-m]

Yes, you got it right, this is exactly what it means. Yeah, there are some rare use cases for on-the-fly processing (think a WYSIWYG editor where the user can choose the size of the image), but for me upfront definitely works best.

[jrochkind1]

Cool. I'd call those two choices "upon upload" (instead of 'upfront'), and "upon first view" (instead of "on the fly"), but I'm sure my terminology would confuse someone else too.