This question here, asks if anyone knows what the mountain in the background picture is. Should we be keeping these questions open? If yes, where is the end to "identify the mountain/dessert/ocean" questions? There's even a "mountain-identifying" tag. Not sure if this makes any sense.
For me the answer to the question "should this be on topic" is emphatically No.
For me one of the major points of SE sites is; to be a repository of useful information (not just answering the askers question but providing a placeholder so someone else doesn't have to ask the same question again).
Number of issues:
Yes, mountain identifying assistance is acceptable. For example, a user may wonder which mountain a park's promotional pamphlet is featuring.
Other users may wonder exactly the same thing. Provided that the question is descriptive other may benefit from it.
It should not be limited to just moutain identifying. They are simply, generally, valid questions.