EW a newish partnership who simply agreed to play "Standard Multi, no strong option."
There don't seem to be universally accepted continuations here.
2M & 3M are clearly p/c.
East thought 4♥ the same, while admitting 2NT would have been safer.
West in turn wondered whether East might even have assumed that they were playing "4♣ = transfer to your major, 4♦ = bid your major" a neat idea but not widely known and not mentioned.