Posting to Instagram
Instagram is a fun, crazy beast. If you post a portrait-size photo, it will try to crop them in crazy ways unless you specifically tell it how.
Follow these instructions for flawless photo postings!
Step by Step
Select the photo

Select the photo
Select from your gallery (or upload from your PC)
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Click "Portrait" Icon

Click "Portrait" Icon
Find the "expand" icon in the lower left. This will select the "portrait" size.
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Now post it!

Now post it!
Continue to post the photo!