Part 1. The "hack"
(Discovered by randomly clicking on a cover with Nene on the japanese actresses Wiki)
1. The link I found was:
https://awsimgsrc.dmm.co.jp/pics_dig/digital/video/real00937/real00937pl.jpg
(This is likely the Amazon solution for image storage or something like that, so this part got me interested)
2. Then, by taking a cover that I was recently interested in:
https://pics.dmm.co.jp/digital/video/ofes00006/ofes00006pl.jpg
3. I just changed the matching part in the end (starting with "video"), and voila, it works:
https://awsimgsrc.dmm.co.jp/pics_dig/digital/video/ofes00006/ofes00006pl.jpg
SO, WE CAN SEARCH ON DMM (or get the DMM link from anywhere, e.g. from JavTrailers), THEN JUST CHANGE THE LINK AND LIKELY GET ANY COVER THAT WE WANT IN HQ!
UPDATE: checked it with DANDY-608; even though the link works, it still gives the standard-resolution version; so, maybe HQ versions are only available for certain studios/labels, etc. or since/for a certain period, titles, etc.
UPDATE 2: also, for AQMB, for example, HQ is available for 029 and 038 but not for the other parts of the series in between; same with KAGP-234 vs. KAGP-263, for example
Still, a good way to get HQ covers to know about
A search idea (adding to the various ideas I've seen on this forum*)
If we could OCR the covers, we could search not just titles and descriptions: sometimes the covers contain the most vivid descriptions and point out the specific things in this video (and not just in the series in general like the title and even the description usually do); for example, in AQMB-038 that I already mentioned, there is stuff like...
がっちりホールドして根元までチ〇ポを丸呑み
ザーメンの喉越しにうっとり
...and other things mentioning deepthroating specifically that aren't in the title (and maybe not even in the description, though this needs to be checked on DUGA, for example)
Naturally, we will need HQ covers for that, and even on Amazon and on official sites of the makers, HQ covers are still more of an exception, and for older titles (~earlier than 2020), they are almost nonexistent, I feel. In any case, these two points are connected
* i.e. creating a crowdsourced database where people would label various titles since many titles are mislabeled, i.e. have the labels that are not realized in the movie or don't have the labels that are, i.e. many DT movies are not labeled as such, or recently I've seen a post where the person mentioned a BJ compilation title that has lots of new-halfs but didn't label the title as such; basically, we could have something like Rule34.xxx or app.rule34.dev but for JAV... or maybe there is already such a thing?
P.S. Okay, sites like Rule34 are called booru, and there are various kinds, and some of them actually contain JAV pictures (even Rule34 itself does, at least in some way and to some extent) and even DVD covers (example); still, they are not JAV-focused