I just had the same thing ..... would be nice to know what the Technical Reason is
for example "out of focus" , "incorrect file size" or "worng file format" .... what does it mean
I like the composition. The cake looks delicious also. It's making my mouth water. Please zoom in at 100 to 200% to inspect you file as you review the issues I've found. The issues are as follows:
The subject is not completely in focus. Most of the edges are soft. (That is not a technical issue)
There is not sufficient depth of field.
There is a white balance issue. It is a bit too yellow.
There is too much highlights.
The edges are not well defined, coupled with the highlights, and incorrect white balance causes plate edge on the left to be blown out,
There is red color fringe in the forefront along the edge of the plate.
This photo seem to have been taken in low light settings indoor. You might also have used auto settings that many times do not adjust accurately, otherwise your white-balance settings was incorrect.
As below read the link about technical issues. There are other rejections reasons including out-of-focus etc.
For your one, although it may be a bit yellow, I don't think there is a white balance issue as I'm guessing the yellow feel is intentional. Your background is yellow I presume. I disagree about the composition. My view is the slice of lemon is not placed as well as it could be. I think the lemon makes the shot unbalanced. It takes away from the triangle (pyramid) shape of the slices of the cake.
There are hundreds of foody shots and it needs to stand out from the crowd.
Again there needs to be a WOW factor.
Technical reasons are about composition, white balance, contrast and saturation.
Have a read of this. It's a brief guide on image quality/Technical reasons:
For your picture though, there are many pet photos. The photo should have the WOW factor. Make it special. Unfortunately, yours is just another photo of a cat!
The green leaves of a plant on the right are distracting, so you need to be careful of what is in the frame of the picture. When looking through the viewfinder, or at the screen, make sure you see what is around the edges of the frame. However, here you can always crop it out.