Hey Tom, I'm the creator. They're actually even worse than what you're describing. On touchscreens, the handle slides up and down as you try to move it left or right. Horrible, isn't it? One of these days, I'll get around to fixing it. The only reason it hasn't been done yet is that, to be perfectly honest, you're the first one to give this feedback. So I appreciate it!
If you got rid of the slider entirely and just had it flick between the two images instantly, the entire handle business would become irrelevant, and you'd never need to think about it again!
I admit I don't do web stuff, so perhaps this is hard to do. But I think it's the ideal. Before/after comparisons are very easy to assess if you can flick between the two cases and let your eyes show you the differences. The value of having an image that's part one and part the other (and two completely separate parts!) seems a bit questionable.
(My line of work means I'm unlikely to end up a customer, so you don't have to pay attention to my opinions.)
The flipping-between is a great hack -- as you said your eyes (really, brain) just do the work for you.
I learnt about it in Japan where proof-readers and editors would (or do) quickly lift a top page up and down to spot mistakes with kanji (pictographs). And sure enough, even from a page of dense script the dissonance of the error really does pop out at you.
I likewise tucked that little trick into my belt -- it comes in useful anytime you're trying to manually spot a pattern across complex data. This technique has the same "vibe" as FFTs to me: it's just neat feeling like you're getting computation from the universe for free.
Solar PV in a similar category: free electrons if you can arrange the magic rocks just right :)
If you put two proofs side by side, you can view from the right distance then uncross or cross your eyes like a stereogram till they converge, which makes differences shimmer.
And once you have the hang of this technique, congratulations! You can now enjoy those 3D "Magic Eye" images that stumped a significant portion of the population back in the 90s :)
I use ScreenFloat[0] in a similar way to catch differences between GUI settings, like the cPanel PHP extensions selector, which has tons of checkboxes. Position a screenshot of settings for site A over the settings for site B, adjust the transparency, and any differences will jump out.
I'd like to imagine I know which of each example were better designed, but the handle going to the side opposite from the label was making me second guess. Move handle away from the label to reveal is how I took it, so hope that's what you intended.
OTOH, I'm on touch screen (iPad/iOS26/WebKit) and it didn't go up and down, it went side to side.
As other feedback, the dumpster fire and deprecation warnings in the docs make me want to try this. I find builder-to-builder candor refreshingly helpful, treating your doc reader like an actual partner instead of like a euphemism. Appreciate your same candor throughout these comments.
Chainlift > Agency Services > Team menu option seems inert.
