There's certainly different shapes, sizes and colours (depending mostly on your skin tone). I'm no medical expert but it could be without the foreskin compressing the glans, it's able to expand a little?
At the end of the day, it's just another part of our anatomy and should not be something afraid to show, Nipples poke out through clothing, mine certainly do. I'm never embarrassed to wear appropriate clothing and don't care if anyone can see an outline. I used to wear speedos to swim laps at the pool, and I've worn lycra shorts when I used to cycle regularly.
yeah it would make sense. A free bellend can flare and grow more if not tightened by a foreskin.
I am quite happy to wear cycling shorts - I did earlier at the gym for a spin session (and I noticed my nipples can be visible especially under tops I wear for exercising). You should get your cycling shorts back on - we may need a TN cycling team for mushroom heads!