The first image is a modern take on pin-ups, I'm fairly sure - the hair, makeup, and shoes seem to fit 2019 better than the 1940s, and the body (thin legs, full butt) is also more in line with what's considered "hot" today than what was seen as desirable during WWII. Compare it to Zoe Mozert's "Tokio or Bust", likely the inspiration. (It just occurs to me ... is the "Come Fly With Me" girl a Nazi??) The second is authentic.

Many pin-up images actually show women in fairly normal clothing for the 1940s, perhaps made out of slinkier, more delicate fabric and with deeper necklines, and in these cases the sexiness comes from the model revealing herself, typically by holding up the skirt or getting it caught on things. Art Frahm's work, for instance, contains many instances of women in everyday dress, out and about, whose underpants (which at the time were loose shorts with thin elastic at the top, or no elastic and a side button or snap fastening) have had a problem and fallen down as their skirts catch on something or are held aloft by the wind. (See "No Time To Lose", from probably about 1945.) Gil Evgren's rather better work achieved a similar effect with more style and a bit less of an exhibition fetish. ("The Right Touch", technically post-war.) As long as a real home-front woman dressed like this wasn't posing provocatively like a pin-up, she wouldn't really stand out as deserving of censure, although a neckline like that of the latter example might have attracted some side-eye and ogling.

The short-shorts seen in many pin-ups, like the second one you've linked in your post ("At Your Command", by Earl MacPherson), are, however, kind of a mixture of bathing-suit bottoms and real shorts. You can see an actual bathing suit in Frahm's "Bathing Pals", and on Betty Grable in her famous 1943 pin-up shot; you can see actual fairly short shorts also on Betty Grable for Yank magazine in the same year, on Lana Turner, "Smooth Sailing" by Pearl Frush, and in this beachwear pattern from 1946. The latter are not made out of a stretchy material and so hang away from the body, and come down to some extent over the thigh. You can see the difference: the pin-up models are portrayed in shorts that are apparently not bathing suits, but they somehow act and are cut like bathing suits. Such a thing did not exist in the 1940s, so it would be impossible for a woman to dress this way in real life. However, she could wear tight shorts with an inseam of just an inch or two in certain situations, namely at the beach or while playing around in the sun, especially if she were younger - the shortest shorts in regular, everyday photography and in magazines tend to show up on teenagers. These, of course, were not typically worn with high heels except in fashion shoots with movie stars, however!

There were no laws against dressing like this in public, but as far as social consequences go ... it's hard to say "what would happen". Obviously, there were men (and women) who would take revealing clothing worn in many circumstances as evidence that a woman was a prostitute and could be assaulted with impunity, but it's not like she would have been drummed out of any store or park. At the same time, many would have perhaps had private thoughts and left her alone. Because women didn't dress/pose exactly like pin-up models, it's very difficult to say what exactly would have gone down in this situation. On the whole, women during World War II walked a tightrope between performative femininity ("you have to keep up standards so you'll feel your best despite the world falling apart and to give the men something to look at!") and avoiding too much sexuality (because their boyfriends and husbands seem to have been constantly suspicious of them encountering other men while working for the war effort or being in a women's military auxiliary).