Why these photos got rejected?

[jeno_ 3737]

[daniellei4510]

Flower images are available by the millions on Adobe Stock's database, so they generally rejected unless they top quality or unique in presentation. In any event, this example is underexposed.

[Ricky336]

Hello,

The first thing that you need to keep in mind is composition. Your shots are not compelling. For the rose, you really ought to choose a better background.

Composition is an important aspect in photography. Read about composition in the following link:

Composition:
https://www.adobe.com/creativecloud/photography/discover/photo-composition.html

Also read about exposure.

Exposure:
https://www.adobe.com/creativecloud/photography/discover/exposure-in-photography.html