Painted in ice-cream shades punctuated with vivid red, the series of portraits made by Picasso in the early weeks of 1932 are as dreamy as love letters. His mistress Marie-Thérèse Walther – we assume it is she – lies adrift in post-coital languor, her body spread before us as a delicious and endlessly fascinating confection.

It is a very human crowd at Victorian Giants: The Birth of Art Photography. There are the slightly melancholic portraits of authoritative and bearded male Victorian eminences, among them Darwin, Tennyson, Carlyle and Sir John Herschel.

Mortality inflects commemoration. So it is with portraiture: the likeness – particularly those which celebrate lives of status and accomplishment – will always be limned with death.

Titian! Mantegna!  Rubens! Dürer! Veronese! Van Dyck! Raphael! Velazquez! About 140 works which were once part of Charles I’s 2,000-strong collection are reunited in a sumptuous collaboration between the Royal Academy and the Royal Collection. It is a marvellous selection covering the 15th to the 17th centuries, the Northern and Southern Renaissance and the baroque.

Dedicated to a foundation stone of western artistic training, this exhibition attempts a celebratory note as the Royal Academy approaches its 250^th anniversary. But if the printed guide handed to visitors offers a detailed overview of working from life, the exhibition itself is a far flimsier construction that never really establishes the purpose of a practice that it simultaneously wants us to believe is thriving today.

What does it take to be included in the Taylor Wessing Photographic Portrait Prize exhibition? This year 2,423 photographers entered 5,717 images: 2,373 of those photographers are left wondering what it takes to make the grade. Remarks from the judges are a little on the Delphic side: "Those we have selected provoked a connection that resonated in all of us."  "It’s always tricky to whittle down to the contenders." "We simply nominated our favourite pictures…".

Some 50 portraits by Paul Cézanne – almost a third of all those the artist painted that have survived – are on view in this quietly sensational exhibition. Eye-opening and heart-breaking, it examines his art exclusively in the context of his portrayal of people for the first time.

This is the latest in a line of beautifully curated, closely focused exhibitions that the Courtauld Gallery does so well. Its subject is the great Russian-French painter Chaim Soutine (1893-1943) who, remarkably, has not had a UK exhibition devoted to his work for 35 years.

I hate biopics about artists in which the portrayal of “genius” is hyped to the point where it becomes a ludicrous cliché. Although I appreciate that, as far as entertainment goes, seeing pigment brushed onto canvas is on a par with watching paint dry, I still can’t forgive directors who resort to dramatic extremes in the hope of evoking the tribulations of the creative process.

As a line flows or falters, registering each slight change in pressure, pause, or occasional reworking, it seems to offer a glimpse into the mind of the artist at work. The line is the instrument of the artist’s eye, the often unpolished, provisional nature of a drawing offering a spark and freshness that tends to gradually lessen as a composition is rethought and worked up in paint.