I think you’re probably correct about the banner.
But they’re in desert uniforms, while the mystery picture isn’t.
Which suggests that the mystery picture was taken in Britain or continental Europe during or, perhaps on some other ceremonial occasion, after WWII.
I’ll hazard a guess that they’re troops of the 1st Czechoslovak Independent Armoured Brigade parading in Britain around the middle of 1944 before deploying to Normandy.
Well, but we are not looking for the picture but for the nation and unit. 
The men on “my” photo are a color guard of the 11th Czechoslovak Infantry Batallion during North Africa Campain. No doubt.
And the mystery photo shows probably the soldiers of the 1st Czechoslovak Independent Armoured Brigade staying guard in Pilsno, after the liberation of this Czech town. ???
Hi Rising Sun* and woj, you got it!
Infact these soldiers are members of the 1st Czechoslovak Indipendent Armoured Brigade. In order to guess the year, and the place (Country) here’s another little clue. The Brigade was created on September 1st, 1943 and equipped with a variety of British and American equipment.
Cheers!
Re-bump! :idea:
Major Sítek’s detachment raising the Czech flag upon crossing the Czech border at Cheb on 1 May 1945?
I’m sorry, dear Mr. Rising Sun*…
these soldiers, from 1st Czechoslovak Indipendent Armour Brigade, are reviewed during their combat training… Not at Czech border and not in 1945…
after the last training before the transportation to the Normandy - May 1944
The colour guard because of the inspection of any VIP ? Montgomery ?, Simonds ?, Eisenhower ?, The King ?
Yes, yes, Mr. woj, you’ve got it!
Here’s the original caption of the picture : Members of the 1st Czechoslovak Indipendent Armour Brigade being reviewed after their training time, at their base camp at Cholmondeley Park near Chester (England), in 1944.
I found this picture on the book “Reinhard Heydrich : assassination!” (Ray R. Cowdery & Peter Vodenka), that’s about the story of Josef Gabcik and Jan Kubis, two members of the above mentioned 1st CIAB, that wounded to death the SS Obergruppenfuhrer and Reichsprotektor of Bohemia & Moravia, Reinhard Heydrich, in Praha on May 27, 1942.
You solved a quite difficult puzzle, congratulations! Your turn… 
woj we await your photo enigma…
Och, sorry guys…
I´ll try to publish my photo at the latest tomorrow
Well, here it is:
When, what nation and army unit:
I apologize my long pause…
Judgin’ by the kind of houses in the background, it seems a country on the Eastern Front… I go for German Army, Ukraine, spring-summer 1943…
Hmmm… what should I say?
It is not Ukraine, they are not Germans and it´s not 1943
I’ve made a hole in the water all along the whole front… Any clues?
The quick initial look made me think Hungarians with a Nimrod 40M but it does not quite look right.
I suggest that It´s a very good way to identify the vehicle first.
I concede that this vehicle was very rare… even just a prototype.
This photo wasn´t taken during the combat and they are not Hungarians.
It seems we need a new clue woj…
OK, here it is:
this unit was formed in February 1937 as the first fully motorised formation of the country…
Judgin’ by the uniforms, they may be part of the Irish Army… Even the houses on the background seem to be part of an Irish landscape… If so, this may be a pre-war training. I go for 1938, Ireland, Irish Army.
Cheers.
Yes, skorzeny57, it is indeed a pre-war training and 1938, but unfortunately… they are not Irish