This small bath has a cement floor with some sort of lineoleum tiles on it. Would it be possible to lay porcelien tile over it?
CAN you? Sure. SHOULD you? Nope. Use a 4" floor scraper and take it up....
DH scraped our old tile up, not only in the bathroom, but a few years later, did the same throughout the rest of the ground floor of our house. I think the tile guy lent him a power scraper/tool (noisy, whatever it was!), which helped make the job go faster and easier. Better off to take up the old stuff if you can.
definitely take that old stuff up first!