Hi. Can anyone tell me what is wrong with the images? The reason for rejection

[Unique Frame Exposure]

The reason for rejection

[RALPH_L]

focus (depth of field) and a little too dark.

[yamato7]

It's blurry.

If it's food, increase the exposure a bit and add yellow to the white balance.

[Ricky336]

Underexposed!

Read about using the histogram.

This shows how your pixels are displayed from dark to light.
https://www.adobe.com/creativecloud/photography/discover/how-to-read-a-histogram.html

[Nancy OShea · Accepted solution]

Poor lighting and aesthetically unappealing.

Compare yours with other food items in Adobe Stock.

What does this have that yours lacks? 

Hope that helps.

[Jill_C]

Blurry, underexposed and not well composed.