How does this work when a photographer or an artist shares a few images? A comic doesn't take long to read.

That would be one problem with it, aside from the coding end, of course (can it even be accomplished -- I don't know).

One solution, from the content creator's end, is to adapt to the system. In the case of sharing photos, the author could write a few paragraphs detailing a bit of the story around how the picture(s) came to be and/or what the picture(s) means to them, etc. As to the comic, well, maybe this isn't the platform for that, if money is the main incentive? But, again, they could add in other things to lengthen viewing time.

Also, and I know this isn't ideal either, viewers (content curators) may decide to wait out the time limit on a post, out of respect to its quality.

Perhaps something like 1 minute, or even 30 seconds, would work better as the time limit. That way people aren't forced to sit idly on a short-post that they think deserves a 100% upvote and bots can't cast 30 100% upvotes in the span of 10 seconds.

EDIT:

Another possible solution is to set different time limits to different lead-tags. The limit could be set at something like 5 ~ 10 seconds for everything with "photography" as the first tag and vary anywhere from 5 seconds to perhaps several minutes, depending on the average length of other posts under those same tags. But talk about going as far north from K.I.S.S. (keep it simple stupid) as possible! Plus, this type of system might lead to a new way to game -- focus on the small time limit tags.