The Christies site describes them as engravings after Rugendas (1666 – 1742) but engraved by Joahnn Daniel Hertz (1693 – 1757). So a later copy.
Interesting because the chaps is what appear to be stocking caps are grenadiers which were not introduced in Austrian service until the 1670s. In most depiction Austrian grenadiers are shown wearing bearskin caps so this is unusual.
There is what appears to be a sergeant with a halberd and wearing a cuirass and morion towards the right hand side. No pikemen are depicted and Austrian infantry are supposed to have been pike and shot units until the general issue of flintlocks in 1699. A number of the privates depicted from fusilier companies seem to have cocked hats ('tricorne') as well.
We can see on detail of an infantry flag which shows the double headed Imperial eagle directed towards the staff on a field of horizontal stripes. Hall & Boeri's Austrian Uniform book has only one colour that is similar which is that of IR Walsegg before 1724 although IR Walsegg was not taken in Austrian service until 1715.
There are partial details of some flags with stripes and coat of arms. These certainly matches the variety to be found in Austrian flags before regulation in the 1740s.
For my money I do not think that this shows Austrians of the 1670s-1690s so much as from the War of Spanish Succession although it does contain some curious features.