M & W - the sides of uprights the being for the most part parallel in an “M” and in the “W” being not very parallel but spreading apart at the base is one way to suss out which either might be when up side down or right side up.
But sometimes it’s the depth of the “V” formed by the uprights.
I’m speaking from having this same sort of problem.
Also you will notice in the “M” at 0600 the (upper) photo is taken with the head of the shell at an angle & and not flat / parallel to the lens plane like in the lower photo so parallax tends to make the upper look more upside down “W-ish” if that is such a word.
Easy to deceive.