Rejection due to low quality

Hello,

To improve, read the following links from Adobe.

User guide:
https://helpx.adobe.com/stock/contributor/user-guide.html
Exposure:
https://www.adobe.com/creativecloud/photography/discover/exposure-in-photography.html
Composition:
https://www.adobe.com/creativecloud/photography/discover/photo-composition.html
Learn and support:
https://helpx.adobe.com/support/stock-contributor.html

White balance:
https://www.adobe.com/creativecloud/photography/discover/white-balance.html

0748: underexposed, artefacts and the blossom is one single red blob with no detail. 

0203: underexposed, and artefacts. You really should disable this fake DOF in your phone, it always creates artefacts that are unrecoverable quality issues. 

2697: underexposed, oversaturated and missing contrast. There is also a chance of having white balance issues. If you check the asset at 100% you see the limits of your small sensor. Fine detail gets "optimized" out.

3125: the asset is underexposed and is missing contrast. But the image has potential, and is probably the best in the series and may be worth to be edited and corrected and submitted again.

First you need to correct exposure and contrast. Then, you need to mask foreground, remove sharpness from the background to hide the deficiencies of the sensor, carefully add sharpness to the foreground. You may need to correct manually some more artefacts. If you can correct the asset in painful and time consuming editing sessions, it may pass. 

3125

I prefer to increase the exposure by about one stop, but doing so makes the ration more noticeable.

0203

I can't tell where the focus is.
In the case of flowers, focusing on the pistil makes the subject clear.

0748

The flower outline is jagged.
You'll need to zoom in to 100% to see it clearly.

2697 is over-saturatted and there's something odd at the bottom of the frame that should be removed.