Hi,
In HikaShop comments ; you can't know if the user is a vendor or not.
The comment system can be configured to allow guest to publish comments and depending your HikaMarket configuration, all users might not have a vendor account.
But you can customize the HikaShop view in order to try to load the corresponding vendor with the user_id.
And then use the HikaShop image Helper to display the vendor image.
Here a thread talking about a similar question :
www.hikashop.com/forum/product-category-...in-product-page.html
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.