Personally since I sell a lot of parts online and especially on tccoa, I would have taken the picture for you. Alot of people don't want to mess with it though.

It seems the newest way of making sure you have something is asking for either a custom angle/pic or having your account page in the background of the picture. It does help people know you actually have the part.

It doesn't mean they will ship it though.

So yeah your request wasn't unreasonable from my perspective but just be prepared that many people aren't as willing as me. Especially when they know the part will sell soon (kooks headers) to someone else who will make it easy for them.

My 2 cents.