Portulaca is a genus of many different species. The most well-known is P. grandiflora AKA moss roses.
Moss Rose (Portulaca grandiflora)
If the flowers are tiny and yellow, it's purslane (P. oleracea.)
Common Purslane (Portulaca oleracea)
If the leaves look like purslane but the flowers are much bigger, it's P. umbraticola, a plant never intended to be used culinarily, sold with annuals as ornamental purslane or the other moss roses.
Wingpod Purslane (Portulaca umbraticola)
Until they bloom, the 2 plants (P. oleracea and umbraticola) look exactly alike. It's not possible from the 1 pic of the plant in question to determine whether it's P. oleracea or umbraticola.
It is said that, like many other kinds of plants harvested culinarily, timing and anatomy matter. Not all parts or individual leaves taste the same at all times, and textural issues may be a factor. For example, I wouldn't use whole, big, tough basil leaves on a sandwich, just the small, tender ones. When zucchini get too big, their flavor & texture changes. It's not something one would eat as a stand-alone food. One doesn't eat a pile of Rosemary, but a little bit can add a lot of flavor to primary menu items.