Also one more thing about that time without shares. As you can see in the end you have found a "high diff" share and your effort didn't change a lot(from 105% to 107% only), so you didn't lose almost anything here because you have solved huge share.
I watch the "transactions" directly in the pool and see how my revenues fluctuate with every block, even though this shouldn't be the case with PPLNS. Yes, each rig mines a dev fee but this is only every one hour for two minutes. I see however huge variations (up to 100% in revenues from block to block) so from minute to minute (since suprnova finds basically all blocks currently).
In the above example. Let's assume a new block was found at 13:36:08. This means all work done from 13:32:12 until 13:36:08 was for nothing, because no shares were submitted, right? It is like if the rig was offline. Since the rig didn't submit any shares from 13:32:12 until 13:36:08 and on average 3-4 blocks were found during this time (all of them found by the pool, let's assume). In case of PROP that would mean zero revenues for those blocks found while the rig submitted zero shares. In case of PPLNS it would still mean some revenues but they would ramp down and be lower than nominal.
The lucky high-diff share found at 13:36:11 will count for the block which started (in oiur assumed example) at 13:36:08. It was found within 3 seconds. It was not the result of the previous four minutes of work, right?
One reason why I don't like too high diffs is because you will often end up with outdated work, i.e. no share found yet while a new block was already found. So the work has to be abandoned and it was for nothing. Yes, miners nowadays at least notice this, abandon the old work and begin with fresh work. Still, it was wasted time if no share was found. In the old days miners would stubbornly continue trying to find a share for the outdated work, wasting even more time, then find it and submit it and trigger a stale share in the pool.