That’s one large file, not sure what the phone was thinking but it contains a bit more than just the picture as dimension wise it is no different than the others and they average between 2 to 4 Mb.
Yes, we take photo’s with a standard smart phone. As in most cases we move about a lot we try to carry as less as possible. Essentially anything you didn’t use the last time, you do not pack the next time. I would suggest to pack the things you missed or couldn’t acquire as long as it passes the airline restrictions of these days.
To Japan we actually took one small suitcase, but it was left behind when moving locally, which was a first in years with the exception of China. I think I can even go without a suitcase to China as there is still clothing left at my in-laws. But better to take one with me, otherwise you stand out and get picked out of the queue by local customs.