Sholem asks:
How was it possible to place the Lechem Haponim before the required time (before Shabbos)? Surely the previous week's production was still on the Shulchan?
Sholem, UK
The Kollel replies:
It seems that it must be that they forgot to place the Lechem on the Table at the correct time on Shabbos, or that some unavoidable circumstances arose which prevented placing them on Shabbos.
[see Arvei Nachal, at the end of Parshas Pikudei, who writes that he did not see anyone who talks about why the Lechem Haponim was placed there in the incorrect way. See also Ketonet Tashbetz Parshat Pekudei].
Chodesh Tov
Dovid Bloom