A measure intended to save the public purse £80,000 a year, give or take.
Lords (with a few exceptions) are not salaried, but they do receive an attendance allowance of between £150 and £300 a day. There are over 800 of them, though not all attend all the time. If they all attended for one day a year less, then at the minimum allowance, the taxpayer would save £120,000.
I suspect there's some politics being played somewhere in all this; there usually is with these things.