As the other person who voted to close this question, I will weigh in here as well (bring on the down votes! (although comments opening up a discussion would be greatly appreciated)).
First, most of the arguments as to why the question deserves to be open here are invalid to use as criteria for a question to be opened or closed. Note that I am not saying this particular questions fail in all of these regards necessarily, but general application of these "leave open" reasons are usually a bad idea.
This question...was well-received, and it got a good, canonical answer
A question being well received does not make it on topic, just like how a question gaining many down votes does not necessarily mean the question should actually be closed (although this is usually the case). There are many instances where high-voted questions are closed, especially due to the HNQ (but not always).
Additionally, questions should not be judged based on their answers or their potential for answers. If this were the case, then any closure policy becomes invalid, as a user could type up an amazing answer to a poor question. An amazing answer could then save the closure of a bad question, which I don't think most users would think should be allowed.
Nobel prizes have been awarded for "identifying things" like radiation, argon, the neutron, the CMB, and many others. The distinction between "identifying" and "explaining" is just semantics.
Identifying things is not unique to physics. And physics is certainly not defined as "the science of identifying things". So identification is not a necessary nor a sufficient condition for a question to be about physics. And even then, not all questions that can be related to physics are on topic here.
I think this is a great question regarding physics of an everyday phenomenon, which is making this SE and physics in general more accessible to non-physicists.
Being about the physics of every day phenomenon or making the site more accessible to other users is also not sufficient to allow a question to remain open. Once again, one could easily make poor questions meeting these criteria. Especially in the latter case: e.g. allowing all homework questions would definitely make the site more accessible to new students of physics.
It is very much in the same spirit as many other popular "everyday physics" questions on this site. E.g. this one about inverted pyramid ice spikes, this one about Oreo's, this one about another shadow effect, and this one about wet tiles.
One shouldn't use currently open questions to determine if a different question should be open or closed. The popularity of questions can be greatly skewed by the HNQ. Also, you can probably find many examples of questions that should have been closed that are currently open. This happens sometimes on meta when users want a homework question to be opened. They dig through past posts until they find a question that slipped through the cracks. On the flip side, we can find popular "physics of every day phenomenon" questions that indeed have been closed, such as this one and another wet tile question. Playing the meta-game of "I can find other questions that prove my point" can easily be played by both sides with no clear winner.
The only thing I see that starts moving in the right direction is
It is a well presented question
Certainly if a question is not well presented it deserves to be closed (usually due to clarity issues). But a question being well presented is not sufficient for it to remain open. For example, there could be really well written questions about a new theory someone has. However, as policy we don't allow questions asking about personal theories because there usually isn't a well-defined answer one can post to the question.
So then, why did I vote to close this question? The OP here is not asking to learn about any physics concepts here. They are just asking, "Hey, what is this?". And while the answer can be stated relating to physical phenomena, like I said earlier, we cannot judge questions based on their answers or potential answers. Additionally, questions like these often are missing a lot of information. Here there is just a picture, and then some information the OP thinks might be useful. Often much speculation is needed, and once answers are posted there are still conflicting answers or thoughts about what is really going on$^*$ (as has started in the comments of the current answer).
$^*$I do not mean to make it seem like I am saying "Don't judge questions based on answers." and then "These questions should be closed because of answers." What I mean by "Don't judge questions based on answers / potential answers" is that it is not valid to say "look at this awesome answer. This question should be open." Because it could very well be the case that the question is complete garbage.
However, this is a Q&A site, where we want definitive answers to questions. If a question cannot garner definitive answers then it should indeed be closed. The various answers could have ranges from good to bad answers, but with varying content. Therefore, this point is still about the quality of the question, not the individual answers it might be able to receive.