It's dimly lit, with more brown than you can shake a stick at. I think the last time I went they'd changed the color of a few of the walls, but it's a long way away from light and airy. There's a metal (heating?) pipe that runs around the perimeter, that you always seem to get your chair leg caught around. There's a definite slant in certain places too.
Decor aside: it's in the city centre, has an extremely well priced menu with plenty of vegan choice and produces consistantly good quality food. It's all veg, gets pretty busy at times and I always end up in there when visiting Exeter (normally a couple of times a year).
It sells the world's best (that I've tasted so far) vegan brownie. There's nothing more annoying than the scores of crap recipes online, from people who think undercooked equals gooey. Herbies use a method for making theirs which I've never heard before, that lets them get gooey on the inside whilst still perfectly cooked. They kindly donated me the recipe, but I haven't permission to post online. No photo either I'm affraid - I never get that far :)
Their burgers appear home made and are pretty decent:
The nachos are really good, and big enough to share. In general the portion sizes are very generous, and they make up a lot of things fresh that others buy in, such as vegan mayo.
I can't recommend Herbies enough. For the price the food is excellent and there's nothing else in Exeter that comes close. If when I next visit I find they've sorted the decor then it'll be even better :)
That sticky toffee pud looks damn good. Nice when you find the odd place that properly caters for vegan deserts rather than your typical apple pie/crumble offerings.