[mrfusion]

I was going to suggest you could use it as a home decoration to make a message everyday but it would only work one day a year?

[saboot]

You'd need the mirror planes to be adjustable in the XY tilt directions. Seems doable though, would be a cool next project

[enchiridion]

Or not? That’s an interesting challenge. Multiple messages depending on the light angle

[ansible]

Sort of the opposite of a digital sundial:

https://www.thingiverse.com/thing:1068443

[fudged71]

It's possible to create artificial light with parallel rays like the sun, you just need a parabolic dish mirror. So in theory yes you could do this at home for everyday projections, just not with the sun.