There is a great chance that photos, which are stored to flash memory, which is solid state memory, which is not affected when power is lost, will be there, right where you left them, once you restore power to your device. You could install a partially charged battery into your phone and then retrieve the important things, like your photos, if you don’t intend to continue using the phone. Else look at replacing the lightning connector assembly. Here: iPhone 6s Lightning Connector Assembly Replacement

NOTE: The logic boards you are placing into your Macbook Pro as a replacement probably are not coming from systems that are current and actively being used (they may have been on the shelf for a while)…more importantly they are almost certainly not coming from systems that were fully updated and running MacOS High Sierra. Realize that if you have updated your Macbook and are running High Sierra, your hard drive has been converted to the latest APFS Apple file system. In order for an older logic board to be able to read any of your APFS hard drive will require that the logic board gets the latest SMC/firmware updates. Without this you will not be able to boot from your hard drive. See how I was able to correct this dilemma here: Hard Drive/OS not recognized after logic board replacement