was soll denn

what ... supposed to, what's … supposed to be?

→ was
phrase Uncommon #16,572
what ... supposed to Denn adds emphasis or expresses surprise; it usually does not mean “then” in this phrase.
GE: Was soll denn jetzt passieren?
EN: What’s supposed to happen now?

Was soll denn das werden?

What is this supposed to be?

— Bullet Train (2022)

Was soll denn jetzt werden mit uns?

So what’s going to happen with us now?

— Der Untergang (2004)

Halt, was soll denn das werden?

Wait, what's this supposed to be?

— Porco Rosso (1992)

Was soll denn aus uns werden?

What will become of us?

— Der Untergang (2004)

Was soll denn sein?

What's the problem?

— I Saw the Devil (2010)

Hagrid, was soll denn das sein?

Hagrid, what's that supposed to be?

— Harry Potter und der Stein der Weisen (2001)

Was soll denn das für eine Gruppe sein?

What kind of group is that supposed to be?

— Der Baader Meinhof Komplex (2008)

Was soll denn das schon wieder heißen?

What is that supposed to mean?

— Interstellar (2014)

Hör mal, Akira, was soll denn hier bitte schön"schon wieder"heißen?

Hey, Akira, what exactly is “again” supposed to mean here?

— Nobody Knows (2004)

Was soll denn aus denen werden?

What’s going to become of them, then?

— Der Baader Meinhof Komplex (2008)

Was soll denn das heißen?

What does that mean?

— Hass (1995)

Was soll denn die Mutti sagen?

What’s Mom supposed to say?

— The Bridge (1959)

Jutta, was soll denn passieren?

Jutta, what's going to happen?

— Das Experiment (2001)

Was soll denn passieren?

What's supposed to happen?

— Alles über meine Mutter (1999)

Was soll denn da draußen so interessant sein?

What could possibly be so interesting out there?

— Gefangen im Kaukasus (1996)

Was soll denn Schlimmes passieren?

What could possibly go wrong?

— Heute gehe ich allein nach Hause (2014)

phrase Uncommon #20,254
what's … supposed to be? Often expresses surprise, annoyance, or disapproval about something.
GE: Was soll denn diese Unordnung?
EN: What’s this mess supposed to be?

Hey, was soll denn das?

Hey, what's that all about?

— The Man from Nowhere (2010)

Was soll denn der rote Lidschatten?

What's with the red eyeshadow?

— Lady Vengeance (2005)

Was soll denn das hier?

What is this all about?

— Memories of Murder (2003)

Was soll denn das, hm?

What's that supposed to mean, huh?

— Das süße Leben (1960)

Was soll denn die Scheiße!

What the hell is this shit!

— Die Welle (2008)

Was soll denn der Schwachsinn?

What is this nonsense?

— Der Sommer mit Mamã (2015)

Was soll denn dieser Lärm?

What's with all this noise?

— Das wandelnde Schloss (2004)

Was soll denn das, du Idiot.

What the hell is this, you idiot?

— The Return - Die Rückkehr (2003)

Aber was soll denn dieser Blödsinn hier?

But what is this nonsense?

— Die Besucher (1993)

Was soll denn das jetzt?

What's the point of this?

— Who Am I – Kein System ist sicher (2014)

Was soll denn das?

What's the point of that?

— Hass (1995)

Was soll denn die Scheiße?

What the hell is this?

— Hass (1995)

Geum-Ja, was soll denn dieser rote Lidschatten?

Geum-Ja, what’s with that red eyeshadow?

— Lady Vengeance (2005)

Was soll denn das ganze Theater?

What’s all the fuss about?

— The Bridge (1959)