Or he could have just sat down at the computer (as a force of habit) without turning it on and turned on his glasses instead.
Still, I don't think this is really all that complicated. The glow in the glasses is the glare from the screen. Dora and Tai are looking at the same page simply because it's coincidence. It's a comic. Things sometime line up that neatly and simply because story has more structure than real life.
However way you want to spin it, the take home message from this strip is "Dale likes Marigold and doesn't know how to tell her" and "up to now, he's being going about it all wrong by stalking her because stalking is bad- (of which the glowing glasses are a reminder of Dale's looming in the alley-way days). And just in case you don't trust wikihow as a source, in an unrelated context, Dora and Tai verify not-stalking as good advice."