The <enclosure> tag, you mean? I think most readers. It's just a place for a link to a multimedia file. I use it for 'photo feeds', posts with only a photo or image. RSS to replace Instagram.
Or that's why you would be good designer. Design world is pretty torn on this tbh. Some designers like effect and some like to be effective. But you can't blame the flashy designers too much. You said it yourself imagine work where "good job" means nobody has noticed anything is wrong. It's kinda hard to sell and measure. Not many people/orgs are sensitive enough to value the "completely obvious" solution that is obvious once you see it but maybe took someone dozens of iterations to come up with.
I'm impressed that it is reasonably usable on mobile. I've built online toys inspired by spirographs and harmonographs and it's a tricky balance to get the image and controls to share a mobile screen space.
Two holes in a horizontal board - drop dowels into each one to act as pendulums. The pivot mechanism for each pendulum was one of those trapezoidal box cutter blades. (In the above illustration I suspect they are nails protruding through a cross-piece.)
Weights are anything you can find. As long as you can move them up and down the dowels to change the period of the pendulums.
A clipboard screwed and glued to the end of one pendulum. The other pendulum has a hinge with the arm holding a pen.
We got our girls, 5 and 2, a Spirograph for Christmas.
With the provided felt tip pen inserted and the outer circle tacked down, I still really struggle to complete circuits without the circles jumping over each other and messing up the drawing.
I don’t remember it being like this as a kid. It felt much more relaxed and natural.
As someone who stupidly committed to laser cutting 30-odd spirographs for my four year old's birthday bag treats last year and ended up realising what a stupid idea that was for that age group - you need to go with ball-tipped pens, be they Bic Biros or whatever.
Crayons are useless, felt tips are too grippy and even pencils aren't much good, as there's too much friction, especially when the hole size is quite tight.
As I remember the trick is to press more toward the ring and not as much sideways. The hardest are when you use a big wheel and use the pen hole nearest the wheels edge - its a bit like the fairground ride that gives you whiplash. I have used glitter ink ballpoints and also pencils with multicolor lead.
Not just regular ball point pens, but with a rather long tip.
You take a modern, generic Bic pen, and the tip is angular. It's a cone shape, ending in the ball point. The Spirograph pens had their ball point at then end of a tube that was about a 1/4" inch long.
I can see if someone pressed really hard, at an angle, how you could bend or break the tip. But it was perfect for Spirograph, because it just went straight in, and was strong enough to drive the gears.
I can see how using modern felt pens may be the modern, common (as in really easy to get off the shelf pens for) solution. But, a felt tip us not a ballpoint and could suffer different issues working with something like a Spirograph (such as splotching).
And stay away from gel pens, what a smeary mess that must be.
I think my cousins and I ruined more than one kitchen table cloth with our inky leaky pens and the spirograph. The physics of the angular momentum I felt gets lost on digital solutions. Is a carnival ride for your hands and fingers.
I remember it being fairly easy to control, and I'm far from a particularly coordinated person! The set came with ball-point pens IIRC though, not something with a felt-tip, so maybe the more solid tip helped maintain control?
Our 4-year-old got a Spirograph Junior for Christmas which he's enjoying - the outer gear in held in place by the frame so there's a bit less to go wrong.
