Nice snapshots, but if you look at the details (zoom in to 100% and 200%), you will see artefacts and noise that make the pictures unsuitable for stock:
The mist pictures has no details left after some aggressive (in-camera) post-processing.
With the mushrooms, it's quite the same, but at a lesser extent. However, you clearly see the noise and the artefacts.
Your iPhone is probably not suitable for such situations.