Some one plz tell me why attached AI images are rejected

Artifacts are easy to spot when you zoom in.

Even if this had been a perfect cutout, remnants of the shadow prior to making the cutout remain.

Your first: everywhere where you see blue, there is a cutout issue:

Your magical sparkles do not look magical to me:

The cutout of your flame is quite impressive, but the flame itself is poorly rendered and, as such, full of artefacts. I post only one example, but when you check your asset at 100% , you'll see plenty of them:

The first image is not cut out well. Look arround the top of the stem.