I first saw this here but was able to reproduce it.

For the image in this tweet, apparently the people who originally made it intended to congratulate Trump but had to change it to ultimately congratulate Biden. But they didn't do a very good job, because there are still remnants of that original message in the image.

You can reproduce this as follows in Gimp or ImageJ (and probably Photoshop, but I don't have access to it)

1. Save the Image from the tweet
2. Open in ImageJ/Gimp
3. Convert the image to (8-bit) grayscale
4. Run the Threshold operation with a threshold of 33

If you do this, you can make out fragments of the original message where it says "Trump" instead of "Biden" and a fragment further down that says "the future of this" or "his" or something like that.

I don't read anything into this except incompetence, but it amused me.