KateH1984 wrote:
… PNG below was designed in Illustrator and exported as a png. I opened a new document and tried setting the New Document Settings as Web and Video & Movie with 72 ppi in RGB as this seems to give the best image quality. I then 'dragged and dropped' the .ai logo file into this document. That was originally designed at 300dpi CMYK. …
way too much 'print'-jargon .... 😉
a) video has no ppi, dpi, etc - whatever dpi you add to your file, it has NO effect on the quality in video
b) video has a 'fix' resolution, 1280x720 or 1920x1080
c) the Preview.app doesn't show the pictures 'real' aspect ratio. and your iM screenshot indicates a square/1:1 picture.
d) video handles no vector-based = .ai graphics, only pixel-based.
I'm not familiar with AI, but it should be possible to create a 1920x1080 png from your sign (btw: nice drawing!)
made a quick'n dirty test with a 'grab' from your post:
possible! 😁
(I'm using Pixelmator for my 'drawings' …)