[mr_mitm]

There is a very obvious dipole in the CMB due to our peculiar velocity. This has been removed in almost all images you saw because it's just an artifact of our particular movement and not physical. It's just the Doppler effect.

This page has three pictures: https://wmap.gsfc.nasa.gov/universe/bb_cosmo_fluct.html

The first is the actual observation. It's boring and looks completely homogeneous.

So you subtract the average value, which brings you to the second picture. Its temperature is 0 on average, but shows the obvious dipole.

When you remove the dipole, you get the last picture, which show only the physical temperature fluctuations.

[kzrdude]

that is a very clear explanation