quite a bit of coloration in trichomes... all the pistils are colored...
how's density of colas?
looks like mid-to-late harvest window to me based on trichomes. FWIW, i prefer an early window harvest, so if i'm a little off on assessment, you'll have to excuse my bias.
use more than one trait to choose your harvest date... take notes of what you did/saw and can try somethign different next time until you find the sweet spot you most prefer. trichomes are probably teh best thing to look at but also use pistil coloration and density of colas (the last one use as little as possible.. .no need to be squeezing colas .. but 1 or 2 times just to be certain is no big deal.) Use all three physical traits you can observe... try out early-middle-late harvests on you own. You may find you like somethign that doesn't quite match teh description others use of it...
bodies do react slightly diffeently to these chemicals... it's worth the effort and once you find the sweet spot you like, it's even easier to recognize it visually.