Time flow in comics is really interesting to me because it depends on text, paneling AND panel content.

Especially when authors want to slow the pace for a while. If they just throw the basic "big, speechless panels" at the reader, they'll just start glossing over them.

BLAME! for example loves creating speedbumps by throwing detailed, visually-slow-to-read designs your way, and frequently expects you to do some visual investigation of your own to not lose the plot.