I'm wondering why this image was rejected for "technical issues", File ID: 126715231.
And is there a way to attach images in this forum instead of inserting in the editor?
I think in general they do not like images with narrow depth of field. In this case, the front of the bird is in focus, and the rear (tail feathers) are blurry. I've also read that there are so many really good bird images already available through the site (maybe a million?) that they only accept new ones if they are truly exceptional.
Thank you for giving us the opportunity to inspect your photo. I do like this one except for a couple of issues I observe. I will first respond to the technical issue rejection.
It would appear there was a camera shake while taking this photo. If you zoom to 100% you will observe a pale line outside the main margin of the birds belly. This is more obvious where the pink feathers meets the white.
The other issue is that your image is not completely in focus. That is another rejection reason. This is what's mentioned by JC, when he speaks of the shallow (narrow) depth of field. Because of this the tail and beak of the bird is out of focus. Unfortunately these errors cannot be corrected using editors.
To upload images to the forum
You may upload images to the forum by clicking on the "Insert Photo" icon which is about the 11th from the left on the menu bar of text box you type your message in. When you hoover the the mouse over it you will see "Insert Photo" highlighted.