1) as you said, its flux is predominantly in the IR
2) it could have been fainter than the sensitivity of the HST instruments but now seen because of the sensitivity of JWST
But given that it appears so bright in the JWST image similar to other nearby galaxies that do appear in the HST image, your bet on #1 seems reasonable.
Also there is another point: rather than a highly redshifted galaxy it could be a very dusty nearby galaxy (also appearing very red) but if I remember right, that would have a slightly different signature. Dusty galaxies often aren't entirely dusty and have "lanes/channels/streaks" of dust that are interspersed among normal stellar regions, so if it were that, you would be seeing some bright spots outside the infrared. But this one has the shape of a normal galaxy but red all over, suggesting something affects the whole galaxy -- i.e. redshift.
Isn't one way to detect redshift to check if there's absorption of certain frequencies due to the light passing through matter on the way here? The absorption will be redshifted as well?
1) as you said, its flux is predominantly in the IR
2) it could have been fainter than the sensitivity of the HST instruments but now seen because of the sensitivity of JWST
But given that it appears so bright in the JWST image similar to other nearby galaxies that do appear in the HST image, your bet on #1 seems reasonable.
Also there is another point: rather than a highly redshifted galaxy it could be a very dusty nearby galaxy (also appearing very red) but if I remember right, that would have a slightly different signature. Dusty galaxies often aren't entirely dusty and have "lanes/channels/streaks" of dust that are interspersed among normal stellar regions, so if it were that, you would be seeing some bright spots outside the infrared. But this one has the shape of a normal galaxy but red all over, suggesting something affects the whole galaxy -- i.e. redshift.