Photos added using GCM wrong orientation in GC

I suspect Garmin are handling the orientation meta-data incorrectly initially

On the contrary, it isn't Garmin's fault at all. I've now experimented with uploading and tacking photos (captured alternately using my Samsung tablet and my Samsung phone, and in different orientations) to activities, both in the Garmin Connect Mobile app for Android, and in Garmin Connect online on my MacBook Pro (running OS X 10.11). In all cases, Garmin just accepts the image file (including EXIF metadata) and preserves it untouched. (I am sure of this; see the last paragraph in this post.) It is the routines in WebKit(?) on the Mac, which I guess are being used by all three browsers in common, that fail to render the images in the correct orientation.

I right-clicked on the snowy photo you showed in one of your screenshots above, and got the URL for the copy of the image where Garmin is hosting it. I'm embedding it below in a pair of IMG tags, so that it will be displayed as an element on a web page outside of Garmin Connect:
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/s3.amazonaws.com\/garmin-connect-prod\/profile_images\/16b84e7f-4731-4ea8-82e2-d4d69b3ed932-5720608.jpg"}[/IMG2]


Yet if you download that image onto your Mac, I bet Preview (or whichever application you use to view JPEG images by default) will display the photo in the correct orientation without asking for user guidance. Even the thumbnail, when I dumped the downloaded file onto my Mac's desktop, is in the correct orientation.

Here's how things look on my MacBook Pro:


Here's how things looks on my iPad Air:


As another experiment, I did the same with the photo that is now showing in the wrong orientation for my dummy activity https://connect.garmin.com/modern/activity/2528230857, in Safari on my Mac. After I downloaded the copy that Garmin is hosting, and compared the MD5 digests of both that file and the original JPEG file, I can ascertain that they are identical.

On my phone, when in GCM when I click on the camera icon to select an image, I see portrait photos rotated 90 degrees anti-clockwise. Do you see this also?

I see portrait photos rotated 90 degrees anti-clockwise. Do you see this also?

Sorta. I find that on multiple Android devices in the Samsung Galaxy range in my household – at least when using Samsung's factory-installed Camera app, and possibly some operating system level camera function access modules – JPEG images are always saved with Dimensions (written into the file's EXIF data) in landscape orientation, but the values of the Orientation field in the EXIF data are variable, depending on how the device was held when taking each picture. If I hold the device in portrait orientation, but with the Home button at the top, when taking a photo the image file is saved with Orientation of 270° (instead of the usual 90°).

When the Garmin Connect Mobile app presents the available stored images as tiles, it apparently ignores the Orientation field. Whether a portrait photo is presented rotated clockwise or anti-clockwise depends on whether its Orientation is 270° or 90°. The app does pay due attention to Orientation when rendering an uploaded photo tacked onto an activity.