Quote: I've made an Icon I want to export as just a circle. So I put my alien in the circle but when I export it, unknown why to me, the rest of it is back even though I deleted the rest of it.
..but where are you sending the icon to ? Some web site / game site / social-something-or-other ?
As Blighty explained all depends how the site displays transparency for png's. However there is another factor. The original pixels are not thrown away just covered by a mask. Some game sites in particular ignore the mask or require a specific colour. (usually black or white]
Example: (very like your first imgur screenshot) https://i.imgur.com/dt6BGxf.jpg
The circular cut-out is ok but if I use the eraser tool and anti-erase mode I can recover the 'cut' pixels.
To prevent that: https://i.imgur.com/RhdvDSW.jpg
Exporting as a png with de-select Save color values from transparent pixels
As a check: https://i.imgur.com/gbE9KSa.jpg
Open that new png and use anti-erase on it. Just a plain background, which is the alpha mask used by the display application to apply transparency.