That doesn’t sound like an ideal situation, although under normal circumstances, it’s probably fine. But yeah, if you don’t have the window sealed up, you’ll probably get more smells than if you don’t. Air does tend to go everywhere. Four feet away is not too close, but you’ll get more scent.
The smells probably aren’t going to hurt you - we go through much more obnoxious exposure to smells on a daily basis, particularly if we live in cities. Or when cooking.
But some people can be sensitive to certain smells (maple hits me hard, the others don’t) you definitely want to reduce exposure to it. For those, you will want to just take a bit more care to seal everything up and keep the smoke outside where it belongs.
So if you’ve got a cardboard panel with the hose running through it - consider something a little sturdier. Maybe a sheet of plywood or plywood and foam with a hole cut into it and a Quick Connect, that can be installed in the window and left there. You can seal around the Quick Connect with silicone, and it won’t leak. (Pictures of our setup below…we removed a sheet of glass and replaced it with an acrylic panel.)
If you have small panes, you can even cut the hole in the acrylic on the Glowie.
But wood or probably a thick foam might work just as well, and it will be insulating as well. 1/4" plywood cut to shape, cut out the end cap hole on the glowforge, install it with silicone, glue up some thick foam core on both sides, and you will have something that you can prop into the window and remove if you don’t want to leave it in.
Or if you want to spend a bundle for the same thing:
https://www.amazon.com/Intake-Vent-Diameter-Adjusts-Through/dp/B01LXS6T8K/ref=sr_1_fkmr0_3?ie=UTF8&qid=1514836077&sr=8-3-fkmr0&keywords=window+vent+for+4+inch+hose
There are lots of options to try for non-permanent installation. (By the way - the one we’ve got is non-permanent - all we have to do to change it out is replace the pane of glass.)