Your dick is big as a leg?
No, but as you can see, the elastic at the base is stretched incredibly thin. Normally it is a lot thicker than that.
If I wanted to, I could stretch out the elastic at the base like she did, but what will happen is that the elastic will lose it's ability to then retighten around my dick, thus completely making using the condom worthless.
I myself use regular sized Magnums, however, the width of the XL condoms would actually fit me perfectly. The thing is, XLs are too long for me which means that using them makes them kinda baggy when I put them on. Because of this there is an incredibly higher chance of breaking. So I use the size below. However, because the size below is too tight, what actually happens is this:
Condoms that are not wide enough for your dick actually CAN AND WILL slide off due to dicks being wider at the base and narrower at the tip.