It is not rotation
Nothing is being turned. Each letter is swapped for a different Unicode character that happens to resemble it upside down — ɐ for a, q for b — and the order is reversed so it reads correctly when the whole line is flipped.
Which means it is real text and can be pasted anywhere, and also that it is not really the letters it looks like.
Where it will not work
Some substitutes are rare characters, and a font without them shows a box instead. Search will not match it, because ɐ is not a as far as any search engine is concerned. Screen readers announce the substitute characters, which makes a flipped display name effectively unreadable to anyone using one.
Fine for a joke in a chat. A poor choice for a username you will keep, and a bad one for anything that has to be found.
Frequently asked questions
Why do some characters show as boxes?
The font lacks that character. The substitutes come from less common parts of Unicode, and support varies by platform.
Can people search for my flipped text?
No. The characters are genuinely different, so nothing matches. Worth knowing before using it in a name you want found.
Is it accessible?
No. A screen reader announces the substitute characters, which does not resemble the intended words.
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