Rywen Yitzhak Mangiel - How did the Ancestors field for Rywen Yitzhak Mangiel get populated?

I did a web search and found this document at "Wirtualny Cmentarz":

https://cemetery.jewish.org.pl/list/c_1/ile_1530

which includes the following text in the row for Rywen Yitzhak Mangel:

"z Zawichostu, żył lat 86, przodkowie: Meir ben Hertzke z Ostrowa i Meir ben Yitzhak Eisenstadt z Sochaczewa (Panim Meorot)"

Google Translate translates this as:

"from Zawichost, lived 86 years, ancestors: Meir ben Hertzke from Ostrów and Meir ben Yitzhak Eisenstadt from Sochaczew (Panim Meorot)"

When I searched for "Panim Meorot", I found this page:

https://www.jewishgen.org/yizkor/sochaczew/so227.html

with this content:

:::
Reb Meir the son of Reb Yitzchak Ajzensztadt
He was the grandson of a sister of the Shach (Siftei Cohen), and the author of the book “Panim Meorot”. He was a rabbinical teacher in Sochaczew. He went from Sochaczew to Worms [3], and from there to other communities. His wife was the daughter of Reb Moshe from Sochaczew – probably the daughter of the aforementioned Reb Moshele Charyf. He died in the year 5504 (1704).

(“Shem Hagedolim Leeretz Hagar”. Paragraph 40. 14.)
:::

Here's the profile for Rabbi Meir ben Yitzchok of Eisenstadt:

Rabbi Meir ben Yitzchok of Eisenstadt, Ponim Meiros, MaHaRaM Asch, I

The information about Rywen's ancestors is written on his gravestone.

Do you mean that you're able to read the inscription on the gravestone, but only see one ancestor mentioned there? Who's the one you see?