What SQL is
SQL here means the statements that move a table into a database: INSERT INTO with a VALUES list, and optionally the CREATE TABLE that defines the columns.
Anyone seeding a database, moving a spreadsheet into an application, or writing a migration.
What PNG is
A lossless image format. Text and thin lines stay exactly as drawn, which is what a table is made of.
Slides, chat messages, issue trackers, and anywhere a table has to travel as a picture rather than as data.
What changes when you convert SQL to PNG
Column names come from the INSERT column list, or from a CREATE TABLE if one is present. Quoted strings are unquoted, doubled quotes are collapsed, and NULL becomes an empty cell.
The table is drawn from the data onto a canvas rather than captured from the page, so the whole thing comes out however long it is and however much of it is on screen. Column widths are measured from the content, alternating rows are shaded, and the scale is adjustable so a table for a slide or a print layout can be drawn at two or three times the size.
What carries over from SQL to PNG
SQL records 5 things about a table that PNG has no way to hold.
SQL knows which of its values are numbers. PNG keeps only their appearance, so nothing downstream can sort or sum them without someone reading them back off the image first.
An empty cell and a missing one are the same thing in PNG, so a null and an empty string in the SQL both come out blank and can no longer be told apart.
Nothing in PNG records that the first row is a header. It is drawn at the top and looks like one, which is all that is left of the distinction.
SQL can be read one record at a time. PNG has to be complete before it means anything, so the whole table is held in memory while it is written and a file that gets cut off part way through is not partly usable - it is unusable.
PNG is the end of the line for this data. Reading the table back out of it is a separate and much harder problem than writing it, so keep the SQL if you will need the values again.