This, from Wild Apricot Support:

This has to do with the fact that Wild Apricot (as well as many other web applications) do not read EXIF data.  On iPhones and other Apple devices especially, when a photo is taken with the camera being held sideways or upside-down, the camera does not correct it.  Instead, it adds some code to the image file called EXIF data, telling the device that is opening the photo the correct orientation.  Computers tend to be able to read this data, so it may look okay before uploading, but the EXIF data is not read once it is uploaded.

To correct the image orientation, you will need to open up the affected images in a program such as Microsoft Paint, and re-save them in a different format (.jpg or .png is best - it's it's already a .jpg, save it as a .png, and vice versa).

>> Reorient the photo as you would like it to appear, before saving.