yours are not smooth and for people with a nice high resolution or just plain large monitor it is going to look like the blockheads from gumby, that is what he was pointing out
Really? You don't get it? You should be getting it because Sheldon explained and then EQnoble explained very well what the issue was. Let me have a go but basically I'll just repeat what both said.
Checkout the edging on your icons, they are rough and jaggy. You see the difference between your rough edged icons and EQnobles example and the example below.